Designing a bay and open water fishing boat

Fall out or off one of those at 60mph, and it would be a serious event !

 

Your responses are the reasons that I am on this site with you. I want the best design for the purpose of the size boat that I want and you guys have been and are a great help. I appreciate your ideas. I like the idea of the trimaran. Catamaran/trimaran boats are a concept in boats that I have always wanted and as I will be spending a good deal of money in a once in a lifetime dream, I will stick with the catamaran/trimaran concept. What I need is your best professional opinions about which one would be best for the purpose. Thanks for hanging in there for me.

 

Also want to add that the primary purpose is for my personal entertainment but secondly, my hopes are to do bowhunting at night for charter. That is also a dream that I want to come true. This, too, is a primary purpose for the size and other designs. Like I said, I want what is best for my money. Again, thanks.

 

Actually, the shallow tunnel boats achieve their goal by compressing the water to move it upwards between the sponsons to feed fairly clean water to the extremely high mounted propeller.
This design runs somewhat contrary to typical schools of thought.
I’m not conversant with the technical terminology, but hopefully you’ll understand how it brings the water up to the prop vs lowering the prop to the water.
About halfway through the video there’s some underway shots of the transom and motor that clearly illustrates this.
Making a single tunnel wide enough for two outboards would be too wide, probably has something to do with wave convergence location between the hulls.

 

Yes, I do understand a good bit about hydraulics. I worked on offshore drilling rigs for 25+ years and hydraulics problems were quite common. Thanks, I do like this idea. I appreciate your help and quick response. One thing that I need to know is on a vessel that is 102" +- wide, what would be the best width for the hulls and the spaces between the tunnels, and how deep should the hulls be from top to bottom?

 

Now you’re getting down to the gritty stuff, and this is where my expertise fades!
I know that there is some science involved in correctly dimensioning a shallow tunnel to do the needed trick, not sure if the guys that manufacture them even use a formula, or if it’s seat of the pants.
My gut tells me that too wide or deep a pocket will not create the desired effect.
I’ve seen some really exotic tunnels and prop pockets with venturis, so maybe there’s even some tweaking of the tunnels roof that could help it perform?

 

A catamaran can never have less draft than the same width monohull.

..the reason the xf boats are monohulls..

your sor (statement of requirements) needs to address the minimum depth water and thus vessel draft Tom

if you want to get in the skinny stuff, the cat may be a problem..

 

In terms of "hull only" draft, that makes sense, but the drive(s) has to be factored in, so there is some variability. Jacking plates another variable.

 

Of course, but Tom needs to develop his minimum depth of water he wishes to bowfish from. If it is 12", you are going to need a boat hull that runs quite a bit shallower...

I am not trying to shatter his high speed planing catamaran dreams, just prevent them from being shattered the first day he wants to get into the shallows..

Most of these big planing cats draft 20" engines up. And so, they are limited practically to 3-4 feet depths.

A 36 foot Twin Vee drafts 22". Getting risky going into 4' deep...one shallow hump...tide wrong..

 

I agree, not ideal for use for shallows.

 

Hey, you guys need to do some research on the shallow water catamarans that are so popular in the Gulf states.
They will run on plane on a wet sidewalk (well maybe 3”) and will float at rest in 6-8”.

 

Jet outboard ? Expensive to run big jet outboards

 

All good, but that boat doesn't go 60mph and it ain't 30'+ long. And the reason it is a flat pad, no bulwarks is they can't afford much weight.