Gulf Coast Crustacean research - Little boat tests for kids

Ok we all were kids and all had some plinker 12ft skiff, a Dink or maybe a little 13ft Boston Whaler. We all had some kind of power but were not necessarily the most efficient ( I had a leaky, cranky piece of junk 5 horse Eska from one of my grand-dads boats myself).
Now if you are looking at putting your kid out there in a small boat - I seriously hope that you have selected a real fiberglass over foam boat with full floatation rather than minimum required. Get a Boston Whaler, Carolina Skiff, something that you can cut in 1/2 and both 1/2's float. Dont put your kid out ther in some hollowed out plastic junk like a Sun Dolphin (a very good boat but not for kids) unless you have filled said Sun Dolphin with Nitro-cellulose or Composite foam.
That said This past weekend we had a few small skiffs out playing and swapping engines. Hopefully this will give you something more to go by than a bunch of advertising hype when you are picking your kids next engine or maybe even boat/engine combo.

Boat 1:
Boston Whaler 13ft Skiff with a Yamaha 40hp outboard engine, Jackplate, electric tilt/trim and an aftermarket prop.
Can you say 61mph? 1.6gph @ 50mph - nice
Boat is rock solid and only ran with the engine stated Handles smooth once on plane, is unsinkable and light enough she gets on plane very quick. An Ideal craft/Engine combo for your more responsible kids. This is not exactly an advanced craft by adult standards but for a kid it would be too tempting to run wide open and hitting a sandbar at that kind of speed can wreck your kid not just the boat/engine. But if you have the more responsible kid, this is a nice economical combination - had it out all day Saturday on 5 gallons of gas - @35mph she sucks .9 gallons per hour and that seems to be her sweet spot for mileage. Cheaper to run than your car.

Boat 2:
Carolina Skiff J12 with a Yanmar D36 Diesel Outboard, aftermarket prop, Jackplate and an aftermarket trim/tilt package
OK now this puppy is slicker than owlshit on a hot tin roof during a rainstorm. Wide open it went through .8 gallons per hour @68mph and .7 gallons per hour @ 60mph. Bear in mind that a diesel of the same horsepower pulls 3 times the torque as a gas engine (rule of thumb - not written in stone) and this Little Yanmar is no exception Prop on it would be at home on a 55 or 60 horse gas and the engine was running open to about 4200-4300rpm and it will definitely go all the way to 4800. Problem is there is not enough boat to pull it off, the owner HAS flipped it trying to get it to that magic 70mph mark. Front end gets too light and it becomes unstable unless you dig the bow down and then you are in for a bumpy ride mon. Since it is a diesel and very easy to maintain one could have the local marina turn the governor in the pump down to an rpm range that would keep a kid from killing themselves, probably use even less fuel and would teach a kid basic good maintenance practices which will carry on in life later to every vehicle they eventually own. Owner regularly runs to Goodland and back on about 5 gallons of diesel per round trip.

Boat 3:
J12 Carolina Skiff with a Yanmar D27 outboard Diesel engine. No trim/tilt Aluminium Bracket mount to keep the engine up, Cam and bolt Tilt adjusters in the bracket but they are the set it and lock the bolt on the cam type.
This is probably the sweeter of the 2 diesels, topped out at 44mph sipping .55 gallons per hour. handled well.
Nice toy, not enough speed to flip it, more than enough to get you there quickly This one has a 15 gallon tank mounted forward - now I may be just a dumb ass redneck but would that not mean a 1000+ mile range?

Boat 4:
12ft Sun Dolphin. Boat has been filled with composite foam. Were it not for the foam this boat used to be a really junky, soft piece of ...... well you know - It just was not safe no matter how pretty they look. Transom plate from factory had bent in from a 10 horse Johnson a couple of year ago when I owned it - it was replaced with a 1/4"aluminium plate going across the whole transom and the hull was filled with composite foam at the same time. Inside of transom mount also recieved a 1/4"aluminium plate. Sun Dolphin did not sell me a quality product here, it was/is a plastic piece of JUNK. ut with the Composite foam in it, it has gotten a lot more stable and does not flex like it did when I first got it. These things come with a plate that says they are rated for a 15 horse - yeah right maybe for the first few hours 'till the transom bends in (they come with like a tinfoil/16ga or 1/8" easily bent transom clip type plate - replace it immediately, fill the boat with foam - DO NOT think that I am joking on this. But since it was handy and we had a few spare engines to try out we used it to compare to the rest of the lineup (boat 5 and 6) which were well made but also underpowered. Now we were more than fair in that we swapped engines around and tried them on different boats so for the purpose of saving some typing, I will list the results after I have listed the other 2 boats.

Boat 5: a Livingston 10' - Now this is one neat boat, double hull design, uncomfortable to run but truly neat looking. No real mods other than a glassed in gas tank and battery compartment.

Boat 6: 11ft Boston Whaler loose gas tank in the center.

Now the above 3 boats had the following engines used , all were tiller control, all were quick throw it on, tithen the 2 hand bolts and set the pin type of thing.

Engine 1: hyped up Evinrude Yachttwin 9.9 with carb and prop from a 15 (makes it a 15 for real) - across the board 1.4 gallons per hour.
on boat: 4 = 19mph
boat: 5 = 17mph
boat: 6 = 22mph

Engine 2: 50's era Johnson 5 and 1/2hp Seahorse 2qts per hour
on boat: 4 = 11mph
boat: 5 = 10.6mph
boat: 6 = 12mph

Engine 3: Tohatsu 8hp four stroke not much more than a quart and a half an hour.

on boat: 4 = 10.4mph
boat: 5 = 10mph
boat: 6 = 11.3mph

Engine 4: marine mover 3.5hp diesel outboard - like a quart all afternoon
on Boat: 4 = Jammin down the waterways at a blazing 9mph
boat: 5 = 8.8mph
boat: 6 = 11mph

Ok so these are just numbers, sounds like someone is doing a boat review or something right? Yup but what I have really done is given some examples of what each craft is capable of with each engine. and while I cant recommend anything, I hope I have at least given you an idea of a guage system so you know what boat/engine combo best suits your kid.