Re: 14 footer 3miles out
Funny you should ask,
2 years ago I took a trip down to the keys with a 14' aluminum Jon and a 8HP Evinrude. Tavernier. Had a blast on the Gulf side, up and down Tavernier creek, through toilet seat pass, but even in 1' to 2' seas it was just too slappy to be on the ocean in a Jon Boat and I turned back a few hundred yards out.
The reason for taking the Jon was towing capacity on my car. So the next year I saved a 13'6" trihull from the scrap yard and redid it with a 15HP Johnson. The beam on this boat was over 5' and way more stable than a Jon. On to Big Pine Key. Another great vacation. We put close to 2 hundred miles on that little boat in 10 days from the Content keys to the Ocean but only once was it calm enough to go out in the Atlantic. There was no chop at all on the water that day, only gentle swells. We ran offshore about a mile and that was as far as I would go in that boat. And a Mile out was twice as far as I thought it was after checking on my GPS.
Now I am dead set on having a light weight boat that can make it 3 miles out to the reef for snorkeling. Islamorada and Hen and Chicks reef is next. So this year I'm working on a 16' trihull (1968 Shell Lake) with a 30HP Johnson (total weight 600#) With that said, I still would not go out in any kind of chop but would wait for a calm day, (if for no other reason than it's just no fun being slapped around) and I would turn back at the first hint of changing seas. Take a VHF radio and if you have any doubts stay inshore.