I've never played with anything but the minmax, but I think its the lightest 8 footer.

If you are looking for fastest with 15 HP, I'd stick with the minmax.  You may be able to put a bigger motor on one of the other hulls for more speed, but without changing motor you probably have it.

There are likely true hydroplane hulls at 8ft that would get more speed, but not with an unmodified fishing motor.  Would need a quickie with a cutter prop, or something like that.

Already having a minmax and 15 HP setup, I'd go for tuning what you have.

Do you know what rpm you are getting now?  You max speed will be obtained close to redline.  Prop choice and motor trim are the most obvious variables.

Max speed will be a compromise with handling.  At max speed tuning, turning ability will be limited as you will tend to ventilate the prop.  At max speed tuning, getting out of the hole will be the most difficult.

So it depends on what you are truly looking for.

My 35 HP minmax is the fastest, most challenging and biggest speed thrill, but the 20 HP minmax is only a few kms slower, is the most enjoyable, and less intimidating to other pilots who try it out.

Just make sure you are trying to get what you actually want.

After finally getting the 20 HP minmax dialed, had I accomplished this earlier, I never would have built the 35 HP minmax.

The outboard motor is a 2 stroke and weight 83 lbs.
My weight is 176 lbs.
Now a have a minimax.

I would like a fast seaflea for a 15hp outboard motor.
And can tell something about the difficulty of building and its sailing characteristics.

I love this video!   Plain, simple language, light hearted and down to earth.  I laughed at your comments about “if you make little mistakes... pffft... who cares?”... LOL.  Great attitude, great fun! 

I’m loving the personal notes and hand drawn plans.  Very simple, “down to earth” and easy to follow... both you and us!