Looking for a long range expedition aluminum power catamaran design

Where can I see those stats or the interior drawings? That sounds like incredible efficiency especially given that displacement, but I don't know what I don't know.

 

Google Search https://www.google.com/search?q=gyro+copter+taking+off+on+wateer&oq=gyro+copter+taking+off+on+wateer&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIJCAEQIRgKGKABMgkIAhAhGAoYoAEyBwgDECEYjwLSAQkxMzAwMGowajeoAgCwAgA&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:2f78af5c,vid:xXncWVz8fzk,st:0
A gyro taking off on water.

 

I'm afraid I don't understand, could you please add some context to this?

 

Yeah, I know all that. The float plane crash i witnessed had a string of repercussions, its not just about safe and secure stowage. I have to assume you have a globally recognized license , radio comms and insurance to fly it, along with all maintenance logs?

A friend wanted to take his motorcycle with him on his cruise, that meant a heavier boat for more stability to operate a small hydraulic crane, which really does not sound like a big ask. The conclusion after 8 years was he would have been better off on a smaller boat, less expenses and maintenance all round, and the fact you can hire a motorcycle almost everywhere there is a tarmac road, should you feel the need. There was also the registration/insurance and mechanical check ups required to keep any insurance valid. If your "toys" are that important to you, they will come at great expense compared to going without. You can always rent an aircraft should you need to keep your licence valid. I cant comment on the semi-submersible, the only one i came across required having a full time operator/service technician onboard.

 

The Troller Yacht Book: A Powerboater's Guide to Crossing Oceans: Buehler, George: 9780393047097: Amazon.com: Books

Its efficient for the reasons you are aiming at in a design. It is actually light displacement for its length. Its D/L ratio is only 105

 

A PPL, the rest I don't see as insurmountable. I know it's paperwork, but so is cruising with pets and fishing and cruising permits and inspections and filing flight plans and a whole bunch of things that are annoying but we put up with to do what we like. I don't view those as obstacles to what we're trying to do. I'm more concerned about actual structural limitations. Yes, a smaller ship that doesn't need to carry any of that would be more economical to operate in the long run, but that's not what we want. We know it costs more to accomodate that and we want to know what it entails, but I still don't understand the claims of 500k extra just for that when other things with similar physical properties aren't an issue. I'm not saying it doesn't cost that much extra, but I'd like to understand why.

The sub for reference: https://sportsub.com/ it's a very simple and compact sub.

Thanks! I'll take a look.

 

I appriciate you do not need a heli-deck or hanger, and if you are aware of the paperwork and regulatory obligations, then you are going in with eyes open.
Im not a big cat fan, but Vietnam seems to be a popular place to get an aluminium cat built if Youtubers are anything to go by, and they are always budget conscious.

 

Thanks, yeah! I don't follow the sailing youtubers closely but it seems the biggest ones end up going that say, albeit for sailing. I didn't know it was Vietnam specifically but I'm not surprised. Should we wait to approach a shipyard until after we have found a NA?

Why aren't you a fan of cats, out of curiosity?

 

I think the 800KG sportsub might be better suited to a wet-dock between 2 watertight bulkheads, requiring only a light crane for the gyro. But on an 81ft Ellermaid type, there is probably the stabilty to carry it in a davit type swing launch/recovery, even if the deck sheer was cut down to reduce heeling moments. Something for a NA to determine.

 

Yards build to plans, usually, so having a design first will allow them to give a project quote.

The "Diesel Ducks" by the designer of Ellermaid, had a build factory in China, but these are steel hulls. I would prefer steel over aluminium just on repair ability anywhere.

Cats definitely have advantages, every boat is a compromise. but they do take up a lot of sq ft in a yard or marina, and it can get expensive just for storage, but im cheap!

 

You have to be careful about loading on cats. There is not a lot of room between adding an extra thousand pounds or not. So, all the more to consult on the SOR. The dig against the cat is the volume tradeoff. And for a highly efficient cat; the hulls are more slender still and then slender hulls offer less weight carrying capability. So, this is why you need to dial it in closely with an expert (like Ad Hoc).

 

This is the "get a NA step"? How do I find a suitable one for this project? I.e. someone whose portfolio aligns with it.

I don't even know what that looks like, let alone what it would involve.

 

Your toys will be a huge factor in design, requiring in addition to storage, launch/retrieval gear, fuel, spares, tools and space to work on and maintain.
A two person crew is going to be very busy just in maintenance and running a boat of this complexity and size, you may never see your partner again, except in the changing of watches.
BTW, don’t forget to factor in the weight of the armor plating!

 

Wet or dry storage dock like this.



Or, like a stern trawler, you could have a semi open stern with a fold down ramp/ closure. If you can put the submersible onto a docking sled, you only might need a winch, rather than a crane.
I dont know how or where you would sling an 800kg load on a catamaran without a detrimental effect.