Looking for a long range expedition aluminum power catamaran design

A place to stow the submersible.

 

This is a free-fall type lifeboat, but the davit system could be used to launch and recover a submersible to a deck or as above, a wet dock. Its same principle, just scale to suit loadings and space.

 

I saw a catamaran with a design that does something like what you describe, could something like that not be used for the gyrocopter, from the upper deck? With a winch it shouldn't be that hard since it has wheels.

This is the catamaran: https://schionningdesign.com/wp-content/uploads/2020/07/Sea-Shanty-1600-Study-Plans-A4-SDI.pdf

Couldn't that be lowered from the upper deck and stowed away in between the deck and the overhang somehow?

 

Interesting that the displacement is shown as 18500kg, with a payload of 6000kg........but the fuel and water add up to around 7600kg itself.

As an example, twin 350 (yanmars as example) would weigh in around 870kg, twin 80s 458kg, would give you an extra 400+kg allowance, but that is still another 400kg plus the lifting system on two fine ended hulls. No doubt if you know the weights you want to accommodate, the hulls could be refined in the aft end to allow extra weight and loading. The gyro is not what i would see as the big issue, its the 800kg lump of submersible.

Why do you perceive that a cat is better for you purpose than a monohull?

 

I looked at monohulls almost exclusively for a while, but it seems that to make one of those fuel efficient you need a really narrow beam that limits the space considerably, both for living and for things like solar generation. Not to mention that I couldn't find designs that accomodated the toys without blowing past a manageable length.

 

What do you consider a "manageable length"?

CATAMARAN Boat plans Power Cat 60 Aluminum

 

Bruce Roberts, steel boat plans, boat building, boatbuilding, steel boat kits, boat kits

 

I guess anything below the point at which I need to have crew, though I'm guessing that's going to vary between ship designs and equipment. I suppose a hard limit would be around 80 ft.

 

80 ft is a big boat for a couple. Lot of wind surface area and a pretty good little sprint to grab lines on a blustery day. Have short handed some boats in that length when transporting them. Doable but a brisk learning curve.


We found a boat we liked about ten years ago, wife took a pic of it and we used Google image search for similar images. Found an old post on the original build, tracked down the builder and was linked to the naval architect involved after some internet sleuthing.


I'd probably pull up pics of boats you like, then do an image search of all similar vessels. That's likely to lead you to a builder or an architect name. From there it's like rolling the dice to hope they are still alive and active....

 

80ft is doable with experience. Bigger barges are run by couples even without the aid of bow thrusters.

 

Indeed, 80 ft would not be my first choice but since we have to set an upper limit that would be it. I'm sure we can manage shorthanding it with practice and good equipment but there's other factors to that after all.

I've seen some designs that look seem like they get close to what we want, but then lack one major requirement or lack important details. I guess reaching out to those architects would be a good idea.

This looks pretty cool if it's possible to fit the toys and enclose the flybridge, but I don't see any details about propulsion or efficiency. Is that usually part of the paid study plans?

 

semi displacement catamarans — Jutson Marine Design https://www.powercatamaran.ca/semi-displacement-catamarans

The 40 footer is running around up here. It looks like it runs pretty efficient, and the add has a computer version similar to what your thinking.


The pics have it fit out spartan as a 20 year old you tuber fits out their "conversion van".

 

Oh wow this is promising. Thank you very much!

 

You could start off by sending PMs (private messages) to @Ad Hoc and @TANSL - they are both very helpful, and they have a lot of design experience when it comes to catamarans.

 

The only way you can establish what compromises are required, either way, is to do a basic design, based upon your SOR.
You can't make informed choices on speculation and words alone.
You need data.