Jet drive, up to 21 ft, deep V, aluminium- plans needed

Hi everyone,

I am in need of complete project for aluminium powerboat. It should include everything needed for fabrication: welding details, craddle design if necessary, details etc.
Preferably proven and tested design in the marine environment.

Length - 17 to 21ft, preferably closer to the upper limit, not longer
Hull type - aluminium, deep V, monohedron
Propulsion- jet drive with inboard gasoline or diesel

If I posted in the wrong section feel free to move the topic.

 

We can design the boat you need, tailored exactly to your needs. We can create a project that will allow you to obtain the CE mark for the vessel. We will then develop all the construction plans, defining each of the parts, numerical control cutting, details, diagrams and assembly instructions, welding lines, parts list, etc.
If you'd like to go into more detail, please send me a PM.

 

Welcome to the Forum Toplicar.

You are smart to look for a "...preferably proven and tested design in the marine environment."
Do you have easy access to building materials?
What do you want the boat to do?
That is, what will you do with the boat?
What are desirable characteristics in its performance?

Do you have any pictures of your current 4m speedboat?

 

Some more information is required
1) Normally jet drive hulls are associated with shallow water running which dictates deadrise angles in the 6 - 12 degree range. If you are looking for a deep V, then there must be another
reason to choose a deep V with a jet. Please provide more information. Speed, purpose of the hull, ie carrying loads, what type of expected wave height, are you using this in shallow
water etc
Question: What degree of V are you looking for?

2) There is a mulitude of proven jet boat designs on the market (albeit at lower deadrise angles as above). These design plans are as cheap as $1,400 US.
The price came off the Specmar website and this included a one time use of a CAD cutting file.
Point: It is not necessary to enlist and commit to the cost of a NEW design with a naval architect

3) There is a mulitude of proven DEEP V boat hull designs that can easily be modified to deal with the jet intake water flow issues. This is much cheaper than hiring a NA

Summary: Provide more information of what you are trying to attain

 

Yes, sir, you're absolutely right. There's no reason to pay the high rates of a na who, on top of that, always complicates everything with theoretical disquisitions that, sometimes, even they don't understand.
That said, I would never buy plans (unless it's for fun) and much less build a boat with them if someone couldn't reliably assure me that "that" beautiful thing floats as it should, is sufficiently stable, and has the proper buoyancy. Whether it will achieve the advertised speed or performance is a secondary consideration, but I'd rather not have anyone jeopardize my safety or that of my family.
"Easily" modifying an existing project can lead to unpleasant surprises. But hey, that's their problem; it will never be mine, because I'll make sure that the modification, even if it isn't "easy," is safe.
My respect for all those who enjoy dangerous adventures (physical or economic).

 

I have welders,fitters,cnc, etc. at my disposal.

I want the boat to have as good as possible seakeeping (smoother ride, less slamming) capabilities for this lenght at higher sea states, for example at 6-7ft waves in case of emergency. Other than seakeeping, a top speed of 40kt would be nice but not necessary.

 

Hi Barry
1) Maybe in US, in Europe we have a lot of jet boats that go nowhere near shallow water. A minimum of 18° deadrise would be nice. Carrying load would be 2 pax, 150L of fuel, engine and jet drive. Other questions I answered in the post above.

2) If there is a multitude of them you could have at least given me a few of them
The truth is there are none that I have managed to find with the requirements mentioned before, that is why I posted to this forum in hope that someone who built or is building something similar either privately or commercially would help me.
The Specmar one you mentioned, I haven't found anyone online who built it to share experiences.

3) This is not a bad idea, I will look into this more

 

This is why I was asking for a proven design, but maybe the requirements are just too specific.

 

Re 2: This is work that you can easily do. Specmar, Cope, Metal Boat Kits, and many more.
18 Degree Deadrise is not a Deep Vee. 21-26 is more applicable.
We have built a couple of 18's and I have been out on the ocean in one with an 18 in 4 foot chop, and it was bone jarring at any speed over 10 knots.

To Toplicar
We built boats from 12 feet to 20 foot outboards, normal deadrise was 12 degrees but some as low as 4 degrees but our main platform were 21 foot boats with V-8 engines 320 - 350 hp
with Kodiak, Berkely (at the time) and Hamilton jets. Most of these were 12 degree V's but a few were 18's

This platform is extremely common and most were designed with a hull that would more than likely see it hitting rocks and submerged stumps/logs at 30 MPH.
We used 1/4 inch bottoms with 6 interior stringers with cross bracing. Around the pump intake, we would double or triple plate the adjacent area. Down the keel we would install either a 7th stringer or
add 1/2 inch by 6 inch reinforcements on each side of the keel joint.

These boats did not have extremely high sides as while the boats could handle 5 - 6 foot standing waves occassionally, for the ocean I would choose a boat with higher sides.

Many of the plan suppliers have boats with this feature as many are used off the west coast of North America.

 

And why a jet drive if it appears that this boat may be only driven in deep water?

 

@Barry ,
I'm not suggesting anything, or at least I haven't intended to. I don't mean to "suggest" anything, but rather to affirm that any change to a boat, including changing the propulsion system and, therefore, the weight distribution, is a very important change that must be handled with care. I'm not suggesting that I'm the only one who can design a safe boat; that would be extremely foolish, and I don't think I've yet reached that level of mental degeneration. I'm not suggesting, I don't want, that a NA intervene. I'm only saying, not suggesting, that it would be advisable to verify that the boat, once the necessary changes have been made, sails correctly. A simple photo, even if not taken by a NA, of a boat with similar modifications under sail could be sufficient, or the opinion of a builder who has performed similar work.
That's all I'm stating, without trying to suggest anything or send subliminal messages.
Cheers.

 

Why does the OP insist on making the boat he wants and not the one you want?. (It's a rhetorical question.)

 

I am not asking you to defend his choice, I was curious as to the why of it.
I am not sure what the kelp-seaweed issue is in the oceans around Croatia but jets often do not handle these very well in the Pacific Northwest. As the OP appears to be new at this, I was
was curious. Certainly not expecting that you are chiding me on asking a simple question.
If he were to enter in a contract with you to design this boat, I would expect that you would ask this question as well as compared to taking his wishes at face value and discuss the merits
of his choice.
Perhaps he is basing his choice on a solid background of information of his needs. Perhaps he is not.

 

Barry, to be completely honest, you are wasting both yours and mine time and energy. If i asked for those specifications there must be a reason behind it. If there are no boat plans that fulfill those requirements you could have simply said so and spend time with your family instead of acting smart with a stranger from the other side of the world online...

 

To be fair, you did post in the powerboat discussion forum, so a quick question as to the why is not far off-topic. If you want, it could be moved to the marketplace forum if you only want exact responses to what you are wanting to buy.