Aggressive Mini Speed Boat Sketch...would it work?

Simply put, if you can't see the clearly obvious flaws, the necessary absorption of a dissertation on hydrodynamics, would be best acquired in another format. There are so many issues and potential issues, that the discussion about them is a bit moot, because it will not work at speeds above 8 MPH. Maybe it would be helpful if you posted a set of 3 dimensional drawings, with the appropriate lines, to define the shape more precisely. And yes, that bow will root around and you'll "swap ends" on a regular basis, assuming you could actually get it to speed, which isn't (not even remotely) likely in the current format. The topsides are highly stylized, congratulations, but this is the last phase of the design process. The hydrostatic and dynamic realities need to be sorted out, before anything else should be considered. It has to be a viable hull form, before any styling exercises are draped over it.

 

go to a place where they sell lot of similar sized water craft, ask the salesman which models have the best performance, most popular with performance minded customers, etc. copy the hull design and than put swoopy/sexy/fancy topsides and eye catching accessories and doo-dads on it (the more the better), just lots of bright eye-catching graphics and build a few. Go to the places where people with more money than sence hang out and start taking orders, you will sell a lot.

Snazzy graphics and sexy appearance is what gets them sold off the show room floor, as long as it behaves decent and performs as good as the compatition, you will out sell everyone else. the type of people that buy these kind of water craft are not navel architects or know anything about hull design, they just want it to show off to their friends.

Make one that looks like a Lamborghini, one like a Ferrari, one like a BMW, and one that looks like an Aston martin, you will have a built-in market for the big spenders that buy those type of cars.

Good luck.

 

Not enough people get that these days. People are looking for something new, fresh, sleek, sexy. Something that matches to modern look of todays technology. I wouldn't want to produce something that just look sexy though. It has to have the performance to back it up. USCG does make that difficult though. With the accessories/doo-dads etc I think it takes finess. You have to have hardware, accessories that accent the lines, but not over the top where it's gaudy. Also, with the right body lines and styling I don't think graphics are needed. Graphics are an easy way to give an otherwise plain looking hull a more modern twist, which is exactly why I am designing some for my Addictor

Thanks for your comment Petros.

 

Just buy a used Sea Doo boat-all the hard work is done- and do some discrete styling cues,but then the aerodynamics would be off.

 

Way to big, way too heavy. My design would be about 4 ft shorter and 800 lbs lighter. Seadoos look small next to your standard runabouts, but when you put it next to a true mini boat (like a 11'-12' they look giant). This boat would be no longer than a small smaller jet ski. Just a bit wider, enough to fit two adults side by side.

 

I work with, an for those folks with more money than sense and they do want want Petros suggests, but they also expect (demand actually) the performance level it exclaims in it's styling. These same senseless folks, will also preform the research (well, their staff will) to find the boat with the performance and styling they want. So, if your boat looks like a 100 MPH craft, but can't get over 50, you'll quickly find yourself with 100k in mold tooling and a few hulls that don't do anything but look more than what they are. I'm not sure where you think your weight savings is coming from, but fast boats, by necessity need to be stiff and strong, which isn't light, unless it's made from really expensive fabrics. Again, without basic dimensions (reconciled), a reasonable weight and moment study, you're just making purrdy pencil sketches.

 

Weight loss from a vessel that's proportionally 3/4 the size would be dramatic just in hull material alone. Read up on the Square Cube Law. It's not hard to see where the weight loss would come from. Then you consider materials like carbon fiber, instead of FRP. It would be simple to lose even more weight than that with the right composites and alloys.

 

Sorry, I got a migraine from looking at the sketch, reminded me of one of those tricky drawings you see on the internet that the mind can't process.

 

Actually a .75 meter cube has a surface area of 3.375 square meters...an extremely simple calculation which I am baffled by the fact you could miscalculate. (.75*.75*6)

but let's help you figure this out.

Let's just say a 1 cubic meter of solid hand laid fiberglass weights 200lbs.

Referring to the Square Cube Law we know that when proportional decreasing the size of an object the new volume(weight) is proportional to the cube of the multiplier (.75*.75*.75=.421875), while the surface area is proportional to the square of the multiplier (.75*.75=.5625)

So weight of our 1 cubic meter object is 200 lbs as I mentioned above.

To find the weight of an object of the same material but .75 the size we must take the weight (200lbs) times the cube of the multiplier (.421875) which gives us 84.37lbs. 115.63 loss in weight.

So our cube has decreased in size by .25% but decreased in volume (weight) by almost 58%.

Seems someone else may need to re-visit the Square Cube Law.

I know exactly what tact means, so don't make me school you on that too.

Now, back to eating my corn flakes...NOM NOM NOM!

 

Sorry, I'll try to refine my sketching abilities before posting any more drawings...just for you, so I don't strain that brain of yours.

 

I like your sketch. Picking at what I know, why the wide chine at the bow? They would only pound on a wave and what do they do. Second the aggressive fins that you added to corner hard in turns. They don't need any thickness, 1/4" is what they need. Thickness is only drag.

 

Thanks man. This bottom concept is almost a stepped hull merged into the chine. I was thinking the chine was actually kinda narrow being lower on the hull than most. The idea was that this would create a low pressure zone behind the sharp, narrow front keel, creating an air pocket behind it reducing the drag on the rear section of the hull. My thoughts were also that this would displace the water out to the sides where it would then close right before the pump.

I agree with the sponsons needing to be as thin as possible especially the lower they get as they would be closer to the water line. I do think they would provide further grip for faster turns and tighter handling...as long as they were designed properly.

Judging by a few of the posts here, the concept and my abstract thinking was a disgrace to boat builders and designers, lol. My apologies.

I do appreciate your insight IMP-ish.

 

Put your drawing in a drawer, then once you have a grasp on the principles, mostly ignored in your sketch, open the drawer and look at your sketch. You'll find the same humor we find in it. We see this sort of thing often, outrageous thoughts, claims and shapes that can't be reconciled or supported hydrodynamicly or with reasonable engineering. It's like an airplane design without an understanding of aerodynamics. Lastly, you "sponsons" will just "trip" the boat in high speed maneuvers and once you've done this in real life, you never attempt to do it again, let alone design a boat with them on it.

 

Simply put... the reality of the laws of physics don't match the drawing.

 

Adam,

You don't suppose a boat that's 3/4 scale should have the same thickness hull as the full scale boat do you? No, wait...I think that is what you are saying. I see now why you can't understand the weight savings. You think an elephant should have the same thickness skin as an ant. Haha! This is too funny.

You don't understand the term Proportional, where if something is scaled PROPORTIONALLY that means the even the thickness of the hull material, the scale of the engine, the controls, everything is scaled incrementally. Air has nothing to do with this as we are not measuring the air space. We are only measuring the volume of the materials that construct the boat.

You take an object that is one unit cube (including all inner workings) even if it is hollow, has an internal structure made of iron...if you scale this object PROPORTIONALLY to 75% the size (or SCALE) it will be 42% the weight.

This does not even take an engineering degree to understand. This is very simple math. I hope to god if you are not a naval architect as you are suggesting, that you can comprehend this. If not, I could understand why they would assign you to larger vessels as you would be building 1800lbs mini boats otherwise, haha!