Our Bulbous Bow addition to Sea Venture - Learn what, why, how, the cost, and if you should . . EP77
ฝัง
- เผยแพร่เมื่อ 30 มิ.ย. 2024
- Part 1 of 2 of our journey from an idea to a reality as we research, decide, and add a bulbous bow to our home and ocean going trawler yacht, Sea Venture.
Link to PassageMaker article: www.passagemaker.com/web-extr...
Link to Bray Yacht Design and Research article: www.brayyachtdesign.bc.ca/arti...
Visit our website: www.CruisingSeaVenture.com
There you will find:
1) Organized links to all our videos
2) Q&A of over 100 questions
3) Our Blog where we provide great information about different topics
4) A link to “Where is Sea Venture right now” along with the current weather
5) A link to Join the Venture Club - club members get more benefits - all for free
6) A history of Sea Venture - with lots of details about the boat
7) A chance to meet the crew and learn more about us and our boating history Lots of fun stuff - so check it out!
Instagram: / cruising_sea_venture
This is our trawler life story.
We retired early and decided to make a big change. We sold everything and moved aboard our 54' Cheoy Lee passagemaker, a “go anywhere in the world”, ocean going power boat.
That was in 2014 and we have never looked back.
Now in our late 50's we are free of work and we are living aboard and cruising our trawler full time.
We have two additional crew members, feline brothers, Blake and Barkley. Yes, we have two brave (sorta) boat cats, on board!
Join us and our crew, on our adventures as we explore new places, discover more about our trawler and what makes her work, and learn more about ourselves in our young retirement years. Our hope is to entertain and inspire you to pursue your own passions through telling our story of our cruising trawler lifestyle.
We end most episodes with a “Trawler Q&A” where we answer your questions.
Thanks for watching, subscribing, and liking Cruising Sea Venture!
Best, Jim, Rosy, Blake and Barkley
Photo Credits:
Photo of Bulbous Bow: safety4sea.com/cm-do-you-know...
Photo of Bulbous Bow Wave Pattern: User:Tosaka~commonswiki, CC BY 3.0 creativecommons.org/licenses/..., via Wikimedia Commons
Photo of USS Lexington: www.warhistoryonline.com/inst...
You are living the dream....it's always been my dream to buy a nice size boat and explore the river systems of the United States with my two childhood friends....we grew up on the banks of the ohio in indiana across from Louisville ky and all our lives we talked and dreamed of retracing the river portion of the lewis and clark expedition....the dream isn't dead yet tho....we are in our 40s so hopefully there's still time.
What an informative video! I've always wondered about the bulbous bow.
Thanks!
Super interesting One of a Kind content.. loved every minute of this very informative
Glad you enjoyed it! Jim
I love your channel and how you explain everything so normal people can understand
Awesome video
Thank you for sharing your knowledge and experience
I'm not a boat owner but like a good book, I could not tear myself away from this posting. I'm a retired US Navy Vet (Vietnam) and your explanation was very captivating. Best of luck. I shared your posting with MV Freedom, a currently stationed Nordhavn out of Seattle.
Wow - you are a heck of an instructor. I have no reason to benefit from your research however, your ability to convey interesting information about a subject very foreign to me personally is very impressive. Thanks for giving me a very pleasant 23 minutes this evening.
Wow the hull looks really good. Great project and very informative. Please keep up the great work!!!
Thank you! Will do! Jim
in the near future. if you experience pitching. examine the amount of room in your chain locker. pickup some used anchor chain that is no longer usable... have it dipped to rid it of corrosion and dipped in something to give it a light corrosion proofing does not have to match your chain or windless .. its not going back over the bow. its going in the bottom of the chain locker with a separation plate over it to keep your anchor chain from tangling in it.. adding bow weight to change the tuning to reduce pitching response speeds.. you could get it cut since its junk chain being used for ballast into 12 foot lengths so its still usable for parking lots between poles also making it easier to fine tune the weight.. not easy to change it out.. but gives you options. paint the end links a florescent color to make it easier to spot to hook them out if need be.. if the boat yard still has the remaining piece of fiberglass tube.. have them lay up a V that could be bonded to the bottom of the tube installed on the hull. this will be just enough to stop or reduce slapping by reducing the amount of flat area on the bottom of the tube when it comes down on the water. might even be able to split the extra section and put it back together backwards giving a convex shape to the bottom of the tube. .
Great ideas. Thanks. We saw a couple of boats in the yard up here that are steel, and had the "V" shape welded to the bottom of the bulb. So far the slapping has been occasional and a small course change during sea trials fixed it. We have only been able to create the noise when it was all white caps out - not our normal boating conditions. Still, great ideas if it develops into a problem worth trying to fix. Thanks so much, Jim
I love this video!! Love the technical ones.
This is s question I've had for sometime. Thank you for addressing it and so throughly.
VERY WELL DONE
This is going to be your best video series yet. Love watching your videos!
This is cool! I am impressed as usual by your thoughts and reasoning. It does seem logical a small deviation in course or speed will decrease the noise. I understand Nordhavns decision given their normal clientele. However like you I am all about function over aesthetics including noise. I am now impatiently waiting on part 2. Thank you and be safe.
Very cool, watching the project come together.
I bow to you...concise and good info.😎
This is one of the best! Really fascinating and informative video. Can't wait for the next installment!
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Great video. What a lot of research you guys have done. As always your tech videos are outstanding.
Nice video and tech talk, looking forward to part 2.
Looking forward to part 2. Always wondered what those bulbs were all about. Great video. Thank you!
Gratz on YT front page! Very informative, always wondered about the bulb.
This is a great informative video. One of the best. Thanks greatly for putting this together. When we buy our long range trawler we’ll consider adding this feature.
Thank you for your location update.
I'm glad for joining . Thank you for the great insight to bulbous bows on ships. Your care in explaining, keeps me happy for I like to know why what and when Thanks Norbert
Thanks, Jim
Very interesting. Thanks for sharing.
Fascinating!!! Can’t wait for part 2
I’m working on finishing the editing now so it won’t be long. Thanks, Jim
Amazing! Thanks for documenting.
amazing again :-). Looking forward to your next video... thanks for sharing your exeriance. thanks for the club
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Really great explanation of the bulbous bow. Thanks for putting this video together.
Glad you enjoyed it! Jim
2 things about bulbous bows
- In rough water it has been shown and proven that a boat with a bulb bow will dig into oncoming waves which drives the front of the boat deeper into the next wave. Boats were designed to "pop up" through the waves, hence the sharp angle and no surfaces that hinder water. So you could put your boat into a wave that it will not recover from and down you go.
- The fuel efficiency you speak of can only be had when the boat is at 1(ONE) certain speed(the sweet spot). This means if your boat sweet spot is 20mph then at 20 is when you will see your fuel efficiency. ANY OTHER speed you will be consuming more fuel as you push that big bulb through the water. These 2 reasons is why Nordhavn stopped putting them on the boats unless customers asked for it.
There are pros and cons to everything and I spent 2 years studying the bulb and based on what I know from personal experience and the research I looked into, the cons far outweigh any pros. I have also been following Nordhavn since 2014 and watched their journey through the bulb as well. One thing to keep in mind is those who want you to have the bulb will tell you all the pros and leave out the most important con and that is your nose submarining in rough water.
Excellent points. Thank you for your perspective. As indicated in the video, our goal was not to make Sea Venture more efficient - that isn't needed, but initial sea trials would indicate that we have increased our average speed by about .5 of a knot, but a lot more time will be required to confirm this initial finding. Regarding burying the bow, unlike Nordhavn's, Sea Venture has a flared bow to reduce this possibility. In the design phase this is was considered, and it's why our bulb only comes out 42" from the hull. What would you consider "rough water". In our 27 years / 40,000 NM of cruising the largest seas we have been in are maybe 10-12' seas in the North Pacific. With today's satellite weather forecasting and weather routers, and given our cruising style, it should not be a problem to avoid anything more. Thanks for watching - hopefully you will watch Part 2 which will come out tomorrow, where you can see a side by side view of the impact on pitching. Thanks, Jim
Excellent! Looking forward to the rest.
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Really great video about your bow project. Well done as usual. Cheers...
Thank you very much! Jim
Anxious to see the results, thanks for sharing.
Michael - Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Very interesting, thanks for the vid.
Hurry up with part 2, ha.
Working on it! Jim
So glad I joined the club so I can get the videos early! 🥳
Brian,
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Thanks for sharing this great information :)
Appreciate the effort you made here! Subscribed
Welcome! Jim
great episode loved the explanation and the installation video portion
Glad you enjoyed it! Jim
That was a fascinating and well described video of everything to do with bulbous bows. I'm extremely impressed with the workmanship as well. Can't wait until the next video. We will be joining the club too. Loved your 'Staged Shot" especially the feet shot as almost every other vlogger shows their feet, lol (not sure why.) Wet gumboots do tell a story. Gee that was a good video.😅🌬⚓🇦🇺🦘
Thanks. We had fun with the "staged" shots. We don't plan any filming. Our normal process is to just grab a camera every once in a while. More often then not, we think, "Oh, that would have been good to film!" We do not cruise to film, instead we just film some while cruising. Just and FYI - if you join the Venture Club you will get an email with a link to Part 2 as soon as I'm done editing, which will probably be sometime midweek. Enjoy and welcome aboard. Jim and Rosy
Very educational and fascinating documentary! Great job guys. Thanks for sharing your adventures with us. Stay safe & warm.
Thank you! Will do! Jim
Dietmar,
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Great video.
I asked the Captain if the Queen Elizabeth one year ago something about its bulbous bow, and she said this is an "Old Ship?" [wow] and that bulbous bows as such were old hat now but I did not get a chance to what she thought was the future.
Interesting history and explanation of the function of a bulbous bow. More gained knowledge from Cruising Sea Venture. Great video, looking forward to part 2.
Glad you enjoyed it! Jim
Mark,
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Love the documentation of the fabrication. Good info too.
Glad you enjoyed it. Jim
Very interesting, thank you.
It’s really cool that your kitties are content being on the boat with you guys.
You’ll probably never get mice either.
I wonder how they prevent the cats from straying when in port, unless they lock them in the cabin? Otherwise a boat cat is a really cool idea.
love that TH-cam suggested your channel to me. you live the life I am trying hard to Live one day. Really enjoyed your camera work on that crummy rainy day! Hope to shake hands one day, Cheers!
Welcome aboard! Thanks, Jim
This episode was soooo interesting that I was wondering if you can expedite part two? LOL.
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Bulbous Bows are nice and all ... But Blake and Barkley are still the real stars of that boat! :-) :-) :-)
Greek War Ships had a RAM at the bow, just below sea level. #1 purpose was to puncture enemy vessels, but they were also known to be FAST !
I am curious to see how it affects anchoring.I think it’s a great idea for the “ride” of the vessel and the fuel savings.thank you for sharing this exciting project!!
Hi Tom, Anchoring is something we will touch on in Part 2. The anchor is in front of the bulb, so it doesn't touch when it goes straight down. I'm still playing with our bridle, which I think will need some adjustments so it doesn't rub against it, or at least we will try to minimize this effect. Thanks for watching, Jim
Wow what a facelift.. so interesting.. sea venture is going warp speed....
An interesting factoid... you mentioned at the beginning of the video that no DeFevers were factory built with a bulbous bow. Our 2007 DeFever 56 Pilothouse "Soulmates" does have a bulbous bow from the factory. But unlike a post-manufacture bulbous bow where it could act as a bumper (a good thing!) because it is separate from the original hull construction, ours is hollow inside. I can crawl into the bulbous bow it from inside the boat. Enjoyed watching the install of your bulb, looking forward to watching Part II.
Jim, Thank you. Learn something new every day. Our friends have a 49 Raised Pilot House DeFever and they had the bulb added and love it. I had never seen a DeFever with a bulb before.
Have you had any issues with yours? Slapping or anything else? I'm kind of glad ours is not open to the inside of the boat. Thanks again for writing and letting me know. Jim
I saw a french steam powered toy boat with a bulbous bow. dated 1907!!
Well, if anything else, what a great place and time to install forward looking sonar.
Karl, We considered it, but it would have literally doubled the cost. The bulb is flooded with Sea Water - (has holes drilled in the top and bottom), which plays an important roll in managing the pitching. Sonar would have required a portion be dry, which would add significantly to the complexity of the item. If we want sometime we can add it to the hull. Our friends have one and thinks it works well when going into bays, etc., but note that it only "sees" about 100 ft ahead and cost about $10K. It sticks down from the hull on their boat. After they wiped one off the hull in ice they added protection around it. You can also get them that retract, but they are even more money. Great idea, but somewhere I think we have to draw some kind of line, even if it's just in the sand.
Thanks for watching, Jim
@@CruisingSeaVenture
I totally get the point about “drawing the line”. That was my weakness.......so the boat had to go before my retirement account went. lol
Nice
Really kool
Super interesting video!!! Like the upped production value with the staged shots. To see that style in the extreme watch a video from Ed Pratt unicycle the world👍👍
Great video and excellent explanation of a bulbous bow. I was very impressed on how clean your hull was. How many nautical miles between anti-fouling paint jobs and what paint was it. Looking forward to part 2. Love your web site.
Hi Glenn,
Glad you are enjoying the videos. We have about 3,500 nm since doing the bottom paint. Its Petit Trinidad SR. Thanks for watching, Jim
Glenn,
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
Darn, now I have to wait for episode #2
I'm working on editing it now. In the meantime, here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
You know you're getting experienced, high quality fiberglass work when one of the craftsmen is smoking a cigarette while fiberglassing!
Exactly! Welcome to Wrangell Alaska, where the crew does not spend the first hour every morning going over OSHA requirements before getting to work. Thanks for watching, Jim
Gentlemen, you're mistaken. That is not a cigarette. It's a covid friendly air filter.
Acetone is VERY flammable.
@ especially if you have an open flame in contact.
@@painlessyachtsaircraft thats how i filter it, muzzle free. unless im sanding then muzzle barely works
Very interesting..The real proof in the pudding will be when you can cruise her again and measure the sea keeping a fuel use.
The bulbous bow was originally used for ramming in the 1800's when we used iron for ships instead of wood. The new war ships of the Civil War had them.
Great! It will be like in the movies, "Ramming speed Captain!" Thanks for watching, Jim
It looks like the sea Venture is smoking a cigar 😂 great job look like a lot of precision work
We have a kids programme over the pond, it’s called Rosie and Jim who live on a canal barge.
Jim, Another viewer mentioned that to us as well. What a coincidence. Thanks so much for watching. Jim
Thanks for the great explanation of the reduced pitching. For those vessels with significant storage or tankage in the bow could the same be achieved by keeping/transferring more weight there?
I've got 5000l of fuel midships but another 3500l bow tank that hasn't seen any fuel for 10 years. Perhaps I should recommission that tank. 😁
Mike, Thanks. From what I learned, on smaller boats like ours, the added weight in the bow does reduce the roll. I didn't include it in the video, because the boat design was so different, but I was reading some research on big ocean going trimarans, and they found the further forward the outriggers where the less the boat pitched. If the stern is heavy and the bow is really lite, then that would make sense. If you have a bow tank that is empty in the bow I would think it would make a difference. The other thought might be that the design of your boat did not randomly put that bow tank up there, it's forward for a reason beyond just available space? Depending on the amount of work to recommission, it wouldn't be hard for you test the theory. Interesting thought. Your total fuel load is about the same as us - Sea Venture is at 8,000L. Thanks for watching. Jim
There are documents in Denny's Shipyard of exploring bulbous bows on sailing ships in the 1800s
Great video, I can’t wait for part 2. Out of curiosity, what bottom paint do you use? Your bottom looked great at haul out.
Hi Shawn, Thanks for watching. We were very happy with how the bottom looked. It all still looked really fresh. It was painted in May of 2020 at Port Townsend when we did the new swim platform. While normally we dive on the hull and clean it, we had not yet done so since it was painted. It is 2 coats of Petit Trinidad SR. They carry it at Fisheries. Thanks again, Jim
Thanks for the reply. I’d say the paint is performing great, especially since it hasn’t been touched since being applied. We’ll need to consider this paint during our next haul. Keep up the great videos.
that big Crash Bulkhead? in areas like SE Alaska with all the logs and tree trunks floating or worse, 3 inches below the surface? AWESOME insurance!!!!
Very informative info. At 15:38 in the video, you were complaining about the 1-1/2" of rain today, and my brain was thinking, you just posted this video a couple hours ago, and back home where I am in Mukilteo we got like 7" of snow today, OK I'm not the sharpest tool in the shed. lol
We walked up to the port office before we started the project - so that would have been the very end of October. Today - Feb 13th, we had a high in the low 30's, the first time it's been above freezing in about 2 weeks. Our kids live in Snohomish / Mill Creek area so we got to see lots of pictures of the snow today. Thanks, Jim
@@CruisingSeaVenture The snow at my son's house in Mill Creek WA was to powdery to build a snowman, but grand kids had a wonderful time sledding, and playing in the snow.
Great video! Can’t wait to see the results. So much contradictory information online about bulbous bows on small boats. Looks like the boatyard crew did a wonderful job installing it.
Thanks for watching! Jim
New subscriber here. Really like your channel. Keep the great vids coming. Question: Does the bulbous bow interfere with anchoring the boat or does it create any issues of the anchor rode chaffing on it?
Great question. The anchor drops right in front of the bulb. It could well rub occasionally on the bridle. We will need to anchor more to see if it's a problem. If so, then we will extend out the anchor roller and/or change up the bridle. Thanks for watching, Jim
Yo - sea venture. Very interesting vid. Thanks. I wonder,tho, how did you determine the shape , size, length, water depth for this bulb ? I see you went with round and mounted not whole distance to bottom of the boat.
Good questions! Shape and size was based on model tank testing studies completed on different hull shapes at the University of British Columbia. Length was based on 1) how far out the bulb could protrude without interfering with anchoring and how far back it had to go to intersect with the hull - in our case, that made the tube 12' long. It's 20% of the beam of Sea Venture. The bottom of the bulb is level with the top of the keel which runs the length of Sea Venture on the bottom of the hull itself. Hope that helps. Thanks for watching, Jim
The design of a this kind of bow is a complex thing. Not just a fiberglass tube. Most times its just make worse.
That is probably why there was so much analysis and expert engagement in the process. So far the results have been good, which is not a surprise given there are a 100 or so boats in the north pacific fishing and cruising with bulbs and I haven't found an owner yet that isn't very happy with the results. You might enjoy part 2 as well. Thanks for watching. Jim
That would be a great location for a camera!
Consider it done! Actually, we did do it. There is a go pro mount built into the top of the bulb. You’ll see it in part two! Thanks, Jim
@@CruisingSeaVenture HAHA! Cool! I've always thought it would be a great way of getting good footage of dolphins and other stuff.
Your kidding, Its a Cliff Hanger... hurry on the 2nd part. Can't wait to see it complete and know how well its been. and how many coats of the bttm paint did you use??. Looks great.. smooth as glass..
Jack,
Here is a link to a 60 second sneak peak at a clip from Part 2 showing the paravanes and bulbous bow during our sea trials. Enjoy. Jim
th-cam.com/video/Q-mqIU5vXQk/w-d-xo.html
wish we got a better view of that yacht fisherman behind you guys 15:49
Very informative, saw a nordhavn 57 with the bulb bow online but a little pricy, also most dont have your fuel capacity?
This is true. Most Nordhavn's do not have our capacity, but with the availability of diesel around the world now, they have enough, usually. We have friends with a 52' Nordhavn that circumnavigated and they had to install diesel fuel bladders on their decks to carry enough fuel for the longer passages. It's all a trade off on weight, living space, how the boats will actually be used, etc. Thanks for watching, Jim
The question is does it make the boat better?did it lower fuel consumption and did it improve the ride ?
It significantly improved the ride and even improved our speed a little.
Great video! Interested in the type of resin they used? What type of fiberglass cloth? I see a lot of the red color in the glass did they use the compound as a bonding step or agent. Was it mixed with the resin for a better Bond?
Charlie,
Fabric is: 1708 Double Bias E-Glass Fiberglass Cloth
Resin: Fiberlay Orthophthalic Laminating Resin
When the catalyst is added to the Resin it turns red so you know it's mixed well.
Great question - I had to text Steve Keller at Keller Fiberglass and ask.
Thanks for watching, Jim
Thank you out standing videos!!
Would this be a good place to mount a forward looking sonar transducer?
We considered it, but . . . It entirely changes how the bulb would work to reduce pitching. The bulb is full of sea water - there is a hole drilled in the top and the bottom, and the added weight of that water having to be pulled up and down plays a big roll. Besides, it would have added about $15K to the total price, so we opted not to. We could always add one in the hull at some point if we want to. Thanks, Jim
I looked at the thumbnail and thought you rammed a WW2 torpedo.
You should have incorporated a fuel tank in the bulbous bow for extra living space in the boat itself.
Two questions, is the bulb free flooding or water tight? Were you able to live aboard during the construction?
Bill,
The bulb is free flooding, with a 2” hole drilled in the top and bottom. Yes, we were able to live on the boat in the yard. Rosy is putting together a video about living on the hard. Thanks for watching, Jim
Noticed that one of your reply's says this will be self flooding, so nearly neutral buoyancy? What would happen if you were able to add or remove water from it, could it be used to trim the boat? Or would the slack in the bulb cause more pitching from the moving water?
Robert, The fiberglass bulb itself added about 1,300 lbs to the bow. With it flooded, if the bulb starts to come out of the water, then it has to also lift the water up that's inside. I would think if it was partially full the water inside would move around, which wouldn't be a good idea. Interesting thought. Thanks for watching. Jim
Does the new bow operate full of sea water? If so, how can it be cleaned out?
So; the bow prevents the boat from traveling uphill both ways.
Most of the bulbous bows on commercial boats on the BC Coast are not circular tubes, but built from 2 half similar pieces, laminated together. Your choice is not typical of today's installs. It takes lots of commercial operation hours before you begin to see payback. 🤔
Steve, understood. Round is the norm in Alaska where there are lots of bulbs. As indicated in our video we have no interest in “payback”. Increased efficiency is not needed or our goal. It would just be a bonus. Thanks for watching. Jim
@@CruisingSeaVenture okay, if dampening is all your looking for, then that lump will certainly provide it.👌
One small nitpick, resin doesn’t dry it cures
Why was the bulb installed about eight inches higher than the bottom of the bow? Wouldn't it be less turbulence if it were flush with the bottom of the bow?
Great question. It's installed even with the bottom of the hull. the section below is the keel. This is so any forces are not transmitted to the keel of the boat but directly spread out over the hull. Thanks, Jim
Idle curiosity here: any idea whether it has been applied to sailboats?
Ken, not that I know of. I know there is currently some research into bulbs on faster boats but I haven't seen anything regarding sail boats. Thanks, Jim
I had a bulbous bow, but then I got a nose job and now I'm feeling a lot better about myself.
That also helps with fuel consumption as well correct? p.s. Hello from a frozen Texas.
We think so, but a lot more testing will be needed to know for sure. It's one of the items covered in Part 2, which will be live on TH-cam at 3pm, PST, just a little less than 2 hours from now. Thanks for watching, Jim
I'm almost but not quite as interested in how a commercial fishing boat captain runs his boat aground and how they got it back afloat. Bet there's a story there!
Yes, I'm sure it's quite a story. I'll try to grab the owner over a beer and ask about it.
What is the pay back period for adding the new bow.
Well, since our primary goal was to reduce pitching, I would say the payback was instant, since it immediately reduced pitching. If you are thinking about improved fuel efficiency, I do not know. Since this was not our goal in adding the bulbous bow we didn't try to do the calculations. If we did pick up a little speed, which it looks like we did (detailed in Part 2 of the video series), the financial payment would be a very long time, since we only burn 3.15 gallons at 7 knots. Thanks for watching, Jim
What engine(s) and tankage does 'Sea Venture' have?
The bottom line Jim, if it makes the cats and Rosy happy it was worth it! We can’t have a unhappy crew.
Also, please explain, in more detail, why a 4 blade propeller is smoother riding than a 3 blade propeller. In what way is it smoother? Thanks.
Ron, My understanding is that a 4-bladed prop causes less cavitation or disturbance of the water around the propeller then a 3-bladed prop, which makes the boat vibrate less, but a 3-bladed prop takes less horsepower to turn at the same speed. I don't understand why this is the case, but it's what I have been told. We have 3-bladed props on Sea Venture. We also had a 3-bladed prop on our old boat. I don't have any experience with 4-bladed props so I don't know how noticeable the difference is, but it must be enough that Nordhavn decided to stay with 4-bladed props. Thanks for watching, Jim
@@CruisingSeaVenture Bering yachts gets truly impressive range with their models, frequently with 5 bladed props. pictures of a Bering 65 under construction show 5 straight slabs of steel, no real "propeller" shape to them in a single engine version, which at 4 or 5 knots gives it a 15,000 nautical mile range. they also have a water tight dry bulbous bow.
I have no idea what it is that gives them the range but if higher number of blades is helping it may be worth investigating.
It might be. I believe on the Bering 65 that might be a feathering prop? That is a propeller that you can adjust the pitch while underway, but I'm not sure. I think prop size needs to be carefully balanced with the manufacturer specs for the engine. Changing props, both number of blades and the pitch changes the load on the engine. I think it can be very easy to get of the spec for your particular engines. For us, we have the props that are set for our engine - plus props are expensive and we have 2 sets already. :) Jim
I thought they were bumpers for ice, floating debris etc.
Did this increase you dock fees because of the added length?
No. Actually the boat is not any longer, since the anchor sticks out further than the bulbous bow. It’s just longer below the waterline. Thanks, Jim
@@CruisingSeaVenture correct me if I'm wrong but does having salt water inside the bulbous result in barnacles
growing and slim attacking the hull inside.
Brandt, We have been told . . . that not much grows inside because there is almost no light, (only from the 1" hole on the top) and not much water movement, which are the two things required for growth. When it was built the interior was coated in epoxy then 5-6 layers of bottom paint were added as well. When we haul the boat out the water the sea water drains out. Then while it's out of the water you plug the bottom hole and fill it with fresh water mixed with some bleach and let it set, so that anything that has grown inside is killed. When we talked to boat owners who had their bulbs damaged in collisions, and thus had the bulbs removed they reported very little inside. Thanks, Jim