Semi-displacement Ocean Crossing

[Jmarsh203]

Great points. All of them.

That answers hulls. But many coastal cruiser SD's don't have window strength, and so forth.

That’s very true for most sd boats, in comparison on my 42 foot aluminum SD trawler I’ve got an aluminum house that has nicely spaced ribs that is pro LT quite a bit stronger than most fiberglass over wood houses. Also quite a few of my windows are 1/2 inch tempered safety glass. I was planning on upgrading all my windows to 1/2 tempered safety glass and upgrade my wood sliding doors to weather proof aluminum sliding doors with a couple dogs and tempered safety glass windows. That combined with my massive fuel tanks and paravane stabilizers I can’t see my sd trawler being any less seaworthy than most sailboats doing crossings on the regular.

 

[Nightflyer]

Here us a Nordhaven for crossing. Adding windows protection covers for crossing among other things.

On some if ny boats I’ve glassed in forward windows and replacement panel windows with port hole windows to handle breaking waves in inlets.

https://youtu.be/dM4NLuNmZOQ

 

[DDW]

That combined with my massive fuel tanks and paravane stabilizers I can’t see my sd trawler being any less seaworthy than most sailboats doing crossings on the regular.

Most "blue water" sailboats have very small ports, on the theory that any port can be broken and the smaller the better. Also, this category of sailboats have an AVS of >130 degrees, some much higher. Equally important is the ratio of area of positive stability to negative stability which should be around 10:1 or greater. When boats are capsized almost all of them are stable upside down, you want the upside down stability to be a minimum so that in any seaway that will capsize it, another sea will quickly be encountered that capsizes it (to upright) again.

Most trawler type yachts would likely suffer superstructure damage in a capsize and flood very quickly. And the AVS is low.

Yachting World has some interesting videos of intentionally capsizing a sailboat, and it is a sobering experience even to watch the video.

 

[bogdang]

Bering yachts are built with a full-displacement steel hull that is capable of crossing any ocean in full safety and comfort.
There is a great summary about the benefits of a Bering vessel here: https://beringyachts.com/yacht-design-construction-approach/

 

[SteveK]

intentionally capsizing a sailboat
Thanks for that link. Imagine in real life the seas would be tossing and additional forces involved. Yet the boat may still survive.

 

[DDW]

Many sailboats have capsized and survived. Powerboats including trawler types seem to capsize and stay that way. Sailboats typically have much higher hull integrity and much higher positive stability. In addition, most sailboat capsizes remove the rig, which increases the positive stability substantially.

 

[bpgt3]

Bering yachts are built with a full-displacement steel hull that is capable of crossing any ocean in full safety and comfort.
There is a great summary about the benefits of a Bering vessel here: https://beringyachts.com/yacht-design-construction-approach/

Great link! Thanks.