I do not have the motor to test this myself. My boat has a 60hp Johnson, but I've been looking for a little Mercury to swap on during duck season for the sole purpose of getting me through shallow water to a few spots. I found an excellent deal on a very low hours 9.9 Merc but I am not sure if it will be enough.
It'll be close but I'm going to say 'doubt it'... How low can you go on the throttle on the 60 and stay on plane? make a mark there and try to plane out with only that much power, I doubt it'll do it.
I have a 2010 Crestliner 1448 Mod v Jon Boat with a 2010 9.9 Mercury 4 stroke and have no problem getting on plane with 2 guys and gear. So Yeah I think one person and some duck gear sure.
Actually I wanna add that it has no issue getting on plane either, actually gets on plane easy. This coming from a guy used to a 90 on a 17 foot tin bass boat. So yeah i would think she would plane, just don;t expect 40 mph or anything funny
With all the 10hp restricted lakes around here I've used several 9.9hp outboards over the years and never had a problem getting my 1648 Lowe on a plane.
assuming you mean just the boat is 300,add bodies,gas,motor, batts, gear,you'll be up to 700 lbs. before you know it. a 9.9 will be working really hard.my 9.9 wouldn't plane a14 ft. v hull with that much weight.even my 15 barely planes.