I would like to know the proper size outboard gas engine that I should
put on a 18-ft aluminum semi-V/deep-V boat.

According to Tracker web site, they stated that the max HP for their
16-ft deep-V aluminum boat is 40HP. I would assume that the max HP of a
similar 18-ft boat "may" be around 50HP (?)

Obviously, this 50HP figure is just the maximum limit. And I may want
something smaller than 50HP to save gas, to reduce noise, to reduce
weight that an electric motor has to pull. But if I go to the other
extreme by getting a very small engine, I may spend too much time
"getting there" especially against the current. Somewhere between the
maximum and the minimum, there may be a horsepower rating that is
appropriate for my need.

Let explain what my needs a
- Put the gas engine in a 18-ft alumimum boat.
- Carry 4 adult males (let's say 750-lb total).
- Use it strictly for fishing, not for skiing.
- I like to drive my car at or below speed limit,
not over it. Likewise, I operate a boat at
moderate speed only.
- Want a quiet engine (I guess I need a 4-stroke
engine).
- Want to save gas money.

What size gas engine should I get? A range of horsepower should be
fine.

Thanks for any info in advance.

Jay Chan