Given the interest in rowing and sailing I think you might like a sailing tender. I have a Dyer Dhow Midget, which is quite small and simple. There are plenty of examples in the 10' range that are better sailboats (with supported masts and sometimes even a jib). I'm surprised not to see many of these on SF Craigslist, they are common on the Seattle one. Here is an example of a larger one:
11' Ranger Sailboat
or a smaller one:
RANGER SAILING DINGHY 8' W/ Full Sail Rig
My dinghy outboard is the 2hp Honda. I bought it used on Craigslist from the original owner. It's extremely simple with no neutral or reverse. It is also a workhorse and reliable and light at about 25lbs (the current version is 30lbs). Gas is no fus, the fuel tank is built in. However the fuel tank is also very small (1 liter) and only lasts about an hour. I mostly use it on my inflatable, but I've stuck it onto my Dyer Dhow Midget too.