Thomas, I would expect it has enough power. A good brand (Standard Horizon has outstanding customer service as well as top product) with a clip of fresh batteries available and a 12v power cord is a great start. If you want more range, put on a masthead 3db or 6db gain antenna and you can always connect the handheld to that for a fast range boost. Don't skimp on the antenna, cable, or actual installation (waterproofed joints, drip loops,proper tie-offs,etc.) either, it makes a difference.
If that doesn't work out well enough for you, consider that you can alway put in a higher power fixed radio later--with nothing else changed or lost, except you'll also have the handheld as a backup to take along to other boats, or to use in the dink.
I've used my antique SH many times when a ships radio was already shut down--and someone forgot to call the dink--or was below and we all need to be on deck--or when I was on someone else's boat and their radio was on the fritz. Built like a brick and valued even higher.(G)