I assume an outdrive is an outboard engine...
If this is correct what is an inboard engine?...an indrive?

if I wanted to have a 24 foot ski boat what is the least amount of
engine I would want to pull a 200 pound man (or woman but I don't know
any 200 pound skiing women) out of the water and drag him around for a
while?

Is there some kind of MPG calculation that is standard for boat
engines? I know that If I drive 140 miles an hour I will get very bad
gas mileage in a car but I was wondering about how gas mileage is
calculated on a boat...

thanks again,
Rogue