This Reckless Design Flaw is Sinking Boats | Step 398 

as i am a retired broadcast engineer i have long felt television is not living up to its promise/use as an educational tool. the two of you have restored my faith in this concept, THANK YOU! add to this the fact that you both are natural teachers (my mother was one and you both remind me of her "style"". Please keep up the great work!!!

It's always cool to see you two get into architect mode!

Excellent rant. I really appreciate your explanations and learning opportunities. Rudders, compartments, bilges and pumps.

Professional commercial mariner here, US tanker fleet for almost 20 years, life-long regatta kid and now cruiser, AND armchair-wannabe-naval architect (since I was a kid as well). THE BEST AND CONCISE AND EASY TO UNDERSTAND explanation (with visual aids!!!) of some really core, but overlooked, principles of naval arch. Nobody gets away from the engineering triangle, “High Quality, Fast Production, Low Expense…chose 2”. But you guys, your work, and your sharing is amazing! Long time subscriber and enjoy your work, helps inspire me on my boat jobs at home. Good luck as the refit continues!!!

I do not sail but I learned a lot today. Thank you very much for this great episode.

I regularly mention in sailing communities that it's absurd to have an offshore boat that could potentially sink from rudder damage. A watertight bulkhead between the rudder and the rest of the boat is a critical design feature necessary for any boat to be considered blue water, IMO. Glad you're talking about this in detail.

Canada here. Well said brother. That wasn't a rant. That was a lesson in " Buyer Beware ". And how to stay alive. Retired renovation carpenter. Love the both of you . And your work.

Hilma Sailing lost their rudder somewhere in the middle of the Pacific back in 2018. It appears that Episode 45 features the ordeal with a few additional episodes discussing the aftermath.

Something to think about is how many, many years from now, if one or both of you starts to lose your memory, you will have all these wonderful videos to look back on to relive this adventure and share with future family and friends.

I have an aluminum 28 ft sailboat which i bought several years ago. It is aged 56 years now and over some years I reinforced it with additional stringers and bulkheads. So now it has 6 watertight bulkheads which are placed corresponding to your ideas of fortifying a boat against water ingress. Even the skeg itself was enlarged and reinforced, because I don't sail regattas anymore but like singlehanded long distance sailing, where rudder agility is counterproductive. I hope that these modifications will be helpful in high latitude sailing which is on my bucket list for the next years. Fair winds to all of you sailing guys out there.

As a 50 yr young American / Italian, I absolutely adore the both of you. I’m happy you’re back working on your sailboat and look forward to your continued adventures across the oceans. I’ve always loved the way you show other cultures and share your experiences and tell your stories. Such talented young couple! So much respect and admiration 🙏🏼❤️🙏🏼

Dan, you did one excellent presentation on why water tight bulk heads are critical to be in any blue water boat! I think what you and Kika are doing is fantastic and you will have a super safe nice yacht when you are all done. It wasn’t a rant, rather an excellent , simplified explanation of the facts. Very well done! 😊🧐🧐⛵️

Our 1977 Rival 38 centre cockpit ketch didn't have any watertight bulkheads. As part of our big refit we have created multiple watertight compartments within the forecabin (plus entry to it that's above the waterline, will have a bolt close watertight door to use at sea). We are creating watertight compartments under the aft cabin bunk for rudder post (will leak a bit around the solid steering connection). Also a coffer dam around our 3 seacocks (2 cockpit drains 1 inlet for watermaker, deck wash etc) and propeller shaft (will leak a bit around the aquadrive).

Dan and Kika hi from Calgary. Dan best sailing channel rant ever. But seriously it all makes sense and you delivered a clear and informative message with passion. I just love how both of you approach a project, with a plan, proper preparation (eg shipping container workshop) logical solutions, not living on the boat while completing the refit, gutting the interior, confirming the issues, hiring professionals when required and hard work. Uma is going to be one helluva boat when its complete.

You make excellent points in this video. I would like to add some input based on many years of offshore sailboat racing. Spade rudders can increase the capability of not sinking the boat by doing a couple of things and these are: 1) Use an internal rudder tube that is very strong and that goes between the inner hull and the cockpit deck. The rudder shaft rides on bearings in this tube; 2) Have the rudder shaft engineered so it is the weak link in the steering system so that if the boat hits something big enough to tear the rudder off, the shaft snaps and you lose the rudder, but not the boat; 3) Carry a spare rudder if you are going offshore. It doesn't take up as much space as you think and if you do lose a rudder (shaft being weak link), you can replace the rudder at sea; and 4) absolutely have a watertight bulkhead between the rudder shaft and the balance of the boat and try to make this watertight compartment as small as possible, even to the point of having a bulkhead before and after the rudder shaft. Another point is bilge pumps. Pretty much all, and I repeat all, bilge pumps installed in commercially manufactured sailboats are there only to remove nuisance water that may accumulate in the bilge. They typically have flow rates of less than 100 GPM (usually less than 50 GPM) and can be overwhelmed by losing a 1" diameter penetration point in the below waterline area. If you are serious about going offshore, look into getting a bilge pump, or bilge pumps, capable of 750 GPM to 1,000 GPM. These may not save the boat in a truly catastrophic incident, but may save the boat in a situation where you lose a hose or fitting on a hull penetration and need time to plug the water entry point. There are commercially available marine grade bilge pumps in this size range and they are not that expensive when compared to looking at total boat loss or having to abandon the boat in a deepwater situation.

We have a Duncanson 43', a 35-year-old blue water cruiser. An Australian designed yacht built to survey standards. 5 watertight compartments including a crash bulkhead fore and aft. All fittings passing through a bulkhead are sealed with bulkhead glands. Even if the main saloon is awash the vessel will remain afloat. Yes, we have a skeg hung rudder, which was tested recently when we ripped off the bottom of the rudder. The skeg was totally undamaged. We sailed 100nm to the nearest lift out facility, lifted the boat, dropped and repairs the rudder in 19 days and continued sailing.

1980 Trintella 44. Front crash compartment. Chain locker is set back such that it is below the waterline. It keeps the weight of chain low and away from the bow. It drains with a 3/4" pipe to the main sump in the saloon. The main sump has a 2000gph bilge pump with an alarm that runs when the pump runs. In addition, there is is a 3700gpm emergency pump, a 2000gph shower bilge pump and a 1500gph engine bilge pump. The rudder is a 3 bearing skeg hung type behind a half height bulkhead. This also drains with a 3/4" pipe to the main saloon sump. The rudder shaft is s/s 90mm diameter at the centre bearing tapering to 60mm at each end to save weight. Built like a brick outhouse😀 the centre bearing is a bronze with a grease gun permanently attached. The rudder will be coming off this winter for the first time in 44 years. The boat has done 40,000nm in the last 10 years alone!

Love the water tight compartment explanation, and so handy that you’re in a boatyard with examples of the rudder types. 🤓

This is along the lines of the lessons we should have learned from the Titanic. Gotta keep the water intrusions compartmentalized. I remember another youtube sailing channel discussing how a spade rudder hit something, bent backwards, and punched a hole right through the hull. It just surprises me that such a design is so prolific.

When you get to installing alarms , use several different types of voices for the alarms so you can tell them apart instantly.

Tusen takk DK for this tip regarding watertight bulkheads. Beneteau Oceanis 500(1988). No watertight bulkheads in this boat. There is a bulkhead in front of the rudder, so it is possible to make this watertight, but a lot of cables and heating ducts going through this at the very bottom, so they must bee sealed of somehow. Also 12! Through hull fittings, but have replaced all of them with Trudesign this year. keep up your magnificent work.

I never would have understood what you were talking about when you were talking about your bulkheads and sectioning off the boat with them until you went over that in this video. At the end of the video I said to myself, it all makes sense to me what they are doing and why. Thank you for using the other boats to explain it, because it now makes me think twice about sailboats and how they are built.

I've enjoyed almost all of your videos, that being said the construction videos are always my favorites.

You guys will soon establish your own boat factory

Oh my goodness. You are almost to Step 400 ! Great Big Hugs ! 🌞⛵️🌴

This is like the best Pearson 36 Pearson never built. I really hope that Uma can sail into her registered home port :) It will be quite the homecoming :)

perhaps underrated highlight of this episode: the Lifting Self Up Through Companionway Drama Noises courtesy of Dan and Kika.

I appreciate explaining the ramifications on the types of rudders and how that flows, pun intended, to bulkhead architecture. Sailing, like life, is about trade offs.

I am so glad you decided to take the old companionway out. With everything else being nearly a clean slate, it makes sense to upgrade the "Front Door".

I have installed a sealed bulkhead forward of each of our rudder Bearings on my Catamaran to mitigate exactly this situation. I have also installed a bulkhead immediately behind our Rudder bearing tube and have attached the tube to the bulkhead to further support the stock, in the event of a collision the rudder stock will break instead of the gland and bearing. Great video again, really love your analysis. Rossco

I am glad that you have brought to everyone's attention just how rudder design has the potential to sink a vessel. Time and time again the same old tired argument of keel design gets rehashed with absolutely no mention of rudder design. And of course, in your discussion you note very clearly the value of a bulkhead forward of the rudder stock. A friend of mine was crewing on a Farr 52 skippered by the late Graeme Ainley in a Sydney to Hobart race, a number of years ago. The rudder was impacted by what the crew believed to be a sunfish or a whale. This caused the bottom bearing of the rudder stock to fracture. Without the bearing in place, the rudder stock thrashed a sizeable hole in the underside of the vessel. Within only a minute or two, the water ingress became unmanageable, and the order was given to man the life raft and a mayday call was made. There was no watertight bulkhead built into that particular vessel. Fortunately, no lives were lost nor injuries incurred during the incident and the crew effectively disembarked their vessel and immediately climbed aboard a fellow competitor's yacht. I remember seeing the skipper and co-owner of the yacht interviewed on television, following the race. His statement to the reporter was something along the lines of: "It's a very sobering experience watching your vessel sink below the ocean's surface from a boat that your meant to be racing against". Graeme and his crew had the good fortune of having such a failure occur in a fleet of maybe 60 or 70 yachts and in favourable conditions. Think about this from a cruiser's perspective. That outcome could have been very different.

Hi guys, wonderful to see Uma being put back together. I’m so glad you decided to restore her not to just do it abandon this wonderful yacht. Uma has such a wonderful character about her and it is your home on the ocean, and I’m so glad she’s going to be so safe without all those ups and downs with the hull Keep up the good work. Love and appreciate you both from Australia.

On Torx Screws! Dear Sailing Uma, I followed you to Svalbard and back to Iceland ... and have 'dropped by' occasionally since. I have been woodworking for almost 50 years, undertaken a traditional wooden boatbuilding course in 2019 / 2020 and been building and repairing wooden railway carriages for the last 2 years. I studied aeronautical engineering at degree level, including a study of materials science, graduating over 30 years ago. I would strongly advise avoiding Torx screws in a marine environment! Stress Corrosion Cracking and Crevice Corrosion are both potential causes of the failure of stainless steel components in a marine environment. Not all Torx fasteners are created equal; can you guarantee that your Torx fasteners are A4 (316) grade stainless? That is more resistant to surface corrosion but the environmental conditions that fasteners experience - tensile stresses and low oxygen chlorine ion rich - are those that are more likely to result in failure. In addition to which, surface contamination of stainless steels with microscopic debris from plain carbon steel tools - screwdriver bits - can also encourage localised pitting corrosion. Furthermore, when it comes to future maintenance or repairs it is so much easier to clear debris, paint or sealant from a slotted screwhead than one with more complex form of socketed or recessed geometry such as Phillips, Posidriv, Square or Torx! Yours Aye GB

I have returned from facing my mortality and am so happy that you guys are still at it and doing so much for encouraging individualism and excellence in creating great entertainment at the same time, if we’re not careful we may learn something.

PREACH!!! You have much wisdom to impart. Do it more!

Much more explanitory videos like this please. This is the reason I have followed you from the beginning. Cheers, keep it up!

Great rant/teaching lesson, fantastic episode. One of your best ever on the building side.

With you two I have learned a lot and knowing that rebuilding a boat takes so much time, money and hard work, the training obtained by you is helping me enormously in the decision of which boat to acquire and what weaknesses and potential problems in each design. Thank you very much for the great contribution you guys give to all of us who are just starting out in this wonderful world of traveling on sailboats. Greetings and many hugs.

You kids answered so many of my questions on how to do projects, at least start them, so much great advice and I know information! Been a long time fan!

Fantastic episode. As someone who's not conversant with boat design (or even sailing), it's great to hear about all the thought going into the refit.

In the UK we call those quarter berths. Here a pilot berth (these days) is above and outboard of the saloon settee (where most boats have storage shelves). Classic Nautor Swans have good examples of both.

Fantastic description and detailed explanation of the rudder and bulkhead design systems and (possible) issues. The planning and forethought you both are putting into this project is simply amazing. Thanks for sharing and informing!!

Thank you for the lessons. I appreciate how you both share your knowledge and experience!

Love the Education moment! That was awesome and so good to know the difference. Thank you for taking the time to share.

My therapist is talking about “compartmentalisation” too 😎 Seriously, you are doing such a great job of making this fun to watch while doing serious stuff! Loving it!

I can hardly wait to see the finished boat.

I love watching boat refits. Can't wait to tackle one of my own. Keep up the awesome work.

I really appreciated this video and Dan's teaching! I found it fascinating!

That was a very informative episode. I learned a lot.

About time someone articulated this. Thanks for helping to publicise this issue I've been harping on about for years

mad respect, just put my sailboat in the water after 5 weeks of straight work. Was getting fussy at the end mainly over other life pressures. You guys are top to bottom rebuilding your boat, thats a lot of work! Thank you for your content :)

absolutely loved the learning opportunity! knowledge transfer from boating redesign to sailing is always top knotch from you two!

Pearson 424. No watertight compartments. One bilge 2 bilge pumps 2 independent lines for each. One high water sensor with a loud alarm and a bilge pump counter in the nav station to make sure somehow we get early warning. She has a skeg protected rudder like your Pearson, a very strong stock and packing gland arrangement and it is relatively small so the chance of it having enough "authority" to command the stock to make a hole in the rudder is very small. That said great idea to have a water tight compartment though !

Excellent explanation! I appreciate you sharing your knowledge.

Wow… INCREDIBLE TEACHING VIDEO…. This is the best teaching of Boat Architect INFO I have ever SEEN or HEARD!

I have watched Billy and Sierra plus Jason and Nikki with their new boats but I have more an interesting an informative experience watching you rebuild your boat. You two are very brave.

Great ep! Just had the one question and couldn't help asking. :)

This is the best info videos you have posted!

The joy of giving an old hull new life with new ideas was inspirational, this demo, refit with improvements of the first build is inspirational. Your fellow sailing families opted to have someone else build their dreams, you are using this time to educate others while providing piece of mind for yourselves. Great travel guides, story tellers, cinematographers, educators. Thank you for all.

Excellent video. The rudder design you were thinking of was transom hung. Like all design these also have issues. The biggest benefit to a skeg wither full skeg or half(Like your boat) is the protection provide by the skeg. Transom hung can have the transom removed from the boat on a object strike if the transom build quality is substandard. I am building my own 40ft sail boat. And I probably going with a fin rudder. As for watertight bulkheads you have to remember the Titanic for this one. If the water tight bulked has openings and the water level ever exceeds the height of the nearest opening(In the case of an opening for chain locker or pilot berth cut out) It serves no purpose. You also have to remember that water weighs alot and this will drastically change the balance of the boat. The saving grace is the bow and stern of a sailboat tend to be above or at the DWL which reduces the amount water that can enter to begin with. For ships there is a design parameter stating how many watertight spaces can be flooded before critical failure as the water tight bulkheads usually stop above the flooded water line. For ships it is 2 compartments. I am not sure if the ABYC has one. Also be wary of over designing your boat. You know have three bilge pumps that need 100% uptime to take care of. My boat will have 1 bilge pocket, 1 main bilge pump, an emergency backup bilge pump, a manual hand pump and an emergency crash pump. This should be the minimum required for any blue water boats. All my bulkheads will be filleted to the hull with small 10mmx10mm openings for drainage to the bilge pocket. P.S Catamarans don't sink. When yachts are made out of fiberglass or wood they are positively buoyant to begin with. The down side to a mono hull is the very heavy weight permanently affixed to the bottom which makes it sink

Great informative video. Well done guys.

Loved this episode. Nice and clear deep-dive into your design choices for an optimal blue water boat.

This was a wonderful explanation bulkhead science. You two have seemingly really considered all the details in this rebuild. Congrats! Can't wait to see the finished project

Great rant. I would also emphasize the importance of watertight bulkheads on twin rudder monohulls where the keel provides no impact protection for the outboard rudders.

My oh my- thanks for a great lesson on “sinking” risk related to lack of water tight areas… no idea as to the risks and potential risk management options! What a marvelous learning opportunity for so many viewers!!! Thanks again

Interesting tutorial on the bulkheads. With multiple bulkheads you should be just as unsinkable as the Titanic. 😆😅😂🤣

Such amazing work and thoughts going into your new boat design.

Orca’s also like to play(attack)with the spade hang rudders….

I agree .A great explanation of good bulkhead planning. Kudos on your renovation so far.

Super interesting video this week! Thank you!

love when you explain stuff

Guys, I understood all of this. Thank you for explaining this so well. I'm very fond of triple back up systems.

Loved it!!! Please more safety/technical rants like this one!

This was very educational....... thank you !

... excellent rant ... a lot of great info included with it ... I don't sail now due to leg loss, but would definitely want to apply your ideas of compartmentalising to my boat ...

Great episode guys!❤

Hello to you I've been following you since the beginning and really appreciate your journey. On the architectural point, I agree 100% with the analysis of creating watertight partitions. This is what I designed, drawn and applied to "Kaahua", I even pushed the concept very far since with structural stations every 60 cm approximately. I literally created watertight boxes between the bottom of the hull and the funds of cofferdams. Then each cofferdams under the floor rises 30 cm above the waterline. Not to mention that the ends are waterproof over the entire height and constitute a reserve of buoyancy greater than the weight of the hull. If the hull were to be punctured, a single cofferdam would fill with 150 liters of water up to the flotation level , that is to say 30 cm below the floor. And if I have an opening lower down (under the cofferdam floor), it is even much less and only half the width because in this part it is also partitioned longitudinally.

We love learning opps! You guys are amazing.

Spectacular episode, Kika & Dan!

I was amazed to learn that the sort of watertight bulkheads are not common or even required for modern boats. A standard engineering safety design review should be driving those sorts of decisions. Great video (as always!)

Enjoyable and worthwhile episode !!!

Most excellent episode! Thanks!

Thank you for your honesty ❤

Well done episode guys!

My future boat will be a Cyber 48 and it has some water tight bulkheads in each hull. That was an eye opener how you explained all of this even though I've seen that video of the boat sinking several times. I didn't even think about how it sunk. This makes me look at things a lot closer. Thanks for sharing!

Thanks interesting. My boat was a Seawind 1160 cat and the rudder hit something hard and bent the stock , there was a bulkhead which was watertight but the actual rudder hole in the hull had a built in fibreglass pipe section which the stock is inserted into and its top is above the water line in fibreglass was so strongly built nothing happened to it . Took huge force to do this and the rudder when bent jammed against the hull and I had to cut some off it to free it next to the hull . But no water at all came in and if It did there is a screw in bulkhead which would slow down enough water anyway. All you’re saying is quite right . Great work . Amazing how strong the fibreglass is on those seawinds. Good work, I think those sail drives are rarely torn off they’re very strong , you’re both great sailors always good work

loved the rant so fun to listen a rant that was so articulate

Really enjoyed the video , very informative.

Well explained 👍

Very well designed, very well explained !!!

Brilllllliant rant - learned alot - thanks for sharing ⛵️ 👍

Well planned. You guys are excellent designers and engineers. 👍👍

Great ideas kids....cannot wait to see the finished product

In making such considered modifications, also employing your experiences with other boats, including racing yachts, I think Uma will feel very different when you get her back on the water. I'm very excited.

Just took my freshly converted electric sailboat out for its first motor trial. Y'all have been a great inspiration for me. Thanks!

Hi! The problem You mention in this epsode is more serious than many people think. Not so far away from You (Gibraltar Strait) and not so long ago (31 October 2023) another sailboat has been lost the way You've described. Polish yacht s/v Grazie Mamma was attacked by killer whales (a common issue on these waters) and lost its rudder. The event lasted roughly 45 minutes. Subsequently the boat with severe leak was being towed by rescuers to the port of Tanger, but flooding was too severe to save it. The boat was probably of Benetteau design with spade rudder. I personally didn't saw it, but I was onboard two other boats (Bavaria-s 38) owned by the same cruise company. Also a spade rudder and (as far as I know) no aft bulkhead. They could be in the same jeopardy after a similar event. Fortunately, they operate on Baltic Sea and Norwegian Coast, not Mediterranean and Canary Islands. Regards, -J. PS. BTW: Those 2 cruises i Was on is so far my only experience with blue water sailing, another one is already planned. And this is all Your fault - I decided to return to sailing after many decades encouraged by watching Your channel. Simply once RU-vid displayed me an episode from Svalbard, when you visited Pyramiden. I was there just a year before, fresh memories and so on... So I fell into this rabbit hole -truly, deeply, madly :) :) :) I binge watched all the current episodes and archival ones from the very begining. Joining two parts of the story took me couple of months, when You reached Scotland. Simultanously I decided for my first blue water sailing voyage...

I love this sailing rant we need more

I watch nearly as soon as you post most times. I have commented a few times. Thank you. Again, thank for creating content that makes my day better. Thanks for being the good people you are. This post is given me more than you post usually do. I cannot explain why. However, I believe you do not always think that a particular posting is so much more than another. How could you? There are so many of us. Just know. That each and every time, it may just be one more for you but that one may speak differently to someone. Today, this one did. Everyone you post has been worth my time, BTW. Still not sure why this one is more special to me. Have a great day.

Fascinating episode guys.

Probably a little late to draw attention to it but having followed last years single hand Golen Globe race, I found the modifications made for companionways quite fascinating. Their website had boat tours and tech details for all the entrants. Boats were all similar vintage to Uma. And watertight bulkheads were an entry requirement. For our 42 ft. Alpa centre cockpit ketch my husband did a clever quick fix for the 2 companionways. Using one inch thick plank that fit the groove, he had three L grooved segments cut horizontally to replace the one piece slider. Much easier to store and very strong. We often left the top one or two out for circulation but were still well protected from the weather. Sorry to "run on" but your video was so great, it gets a person thinking of what works and what doesn't. You look like you are well on your way to "what works". She'll be a great boat to sail.