Another boat I'm looking at is a fiberglass one(I swore I'd only get aluminum, but my wife thinks It's pretty) It's a forester 160 sport, which, according to the website I found, weighs around 1800 lbs. It has a 75 merc. The dealer says it's only rated for 80. Am I right to look at the weight and think this boat is underpowered? Or is weight the factor I should be looking at? I'm looking to fish and ski, so power is kind of important to me.