Laughing Stock of the Marina...

[CalebD]

Sarafina,
I know you don't feel as though you are the first to discover the wonders of using an outboard 2 stroke engine. Just to confirm that you are in an elite club I will add that I once helped a friend take his MacGregor 26 S from Fire Island Inlet to NYC (about 50 nm.) in calm weather.
What we had not accounted for was the ebbing tide of the Great South Bay into the Atlantic which was kicking up about 10' + waves while we bobbed about in the MacGregor as the small 8 HP - 2 stroke engine occasionally saw some air and complained. We made it out of the inlet and once out on the ocean all was fine as we motored and tried to keep our 5 knot speed towards NY Harbor. We made it by 8:00 PM (2000) as the sun had set and filled our gas portable gas tanks at the marina there. The only thing we forgot was the 2 stroke oil as the boat was new to my friend and new owner of the boat.
The next morning we were able to motor out of the marina (before being charged for an overnight fee) when the engine died and we raised sails and sailed up the Hudson River. Our tacks on the Manhattan side were like subway stops as we made it to 14th St. then 23rd St, 32dn, 42nd etc. in the rising flood tide. By the time we got to Yonkers the tide in the river turned and we had still not revived the 8 HP Evinrude engine. We pulled the boat along the shore to the ramp and pulled her out after pissing off a few fishermen who had their lines in the river.
Embarrassment is universal and we realized that we had forgotten to add the 2 stroke oil to the gas down in Manhattan (NJ - actually) which caused the engine to be sleepy.
My own boat (Tartan 27' from 1967) has an Atomic 4 gas engine in it that is rated at somewhere between 20 & 30 HP. A Cal 28 in SF Bay should not have a 20 HP outboard in my minds eye. Outboards and inboard engines are different devils that you need to know about but I would not advise you to put a heavier engine on your transom then you can easily lift. Inboard engines are clearly the way to go for boats that are this big, IMHO. You will want all the HP you can get at some point when battling the bars and waves that guard the inlet to SF Bay.
YMMV (your mileage may vary).
My best.

[Boracay]

Wikipedia has a nice article on hull speed (any faster and you're digging a hole in the water).

Just fuzz out the really technical bits.

[Solitude]

Originally Posted by Boracay

Wikipedia has a nice article on hull speed (any faster and you're digging a hole in the water).

Just fuzz out the really technical bits.

Yes hull speed is the deciding factor and thats true in current as well. I would think that you would want your engine to make hull speed in flat calm water and then factor in wind. Go up a few HP.

Sarafina : I have never seen a 20hp outboard on a sailboat around here. Having said that I have seen many 20HP deisels in boats of your size.