long shaft or short shaft

Measure the transom from keel to the 'hook' of the motor bracket- it should be ~15", ~20" or ~25 (+/- an inch or so). The plate above the prop is usually level with the keel.
The short/long/xlong dispute is mainly among smaller boats; in a 23-footer, the engine should have been mounted and rigged by someone who knew what he was doing.

 

I sure it was done at a marina. Why I asked was because the owner said the last owner had a short shaft on the boat ,with 500 lbs of sand in the bow. It had big trim tabs also. Something wasn't right? I didn't buy the boat. I was very disappointed.

 

Tunnel Hull Setup

Bill K - check out AeroMarine web site for setup tips on tunnel hulls. You really should have a short shaft motor for your hull, as you need to mount high on transom, and also don't want a high center of gravity for safe handling. Your motor looks like a short-mid/shaft, so you should be fine for that hull. If you'd like more info on your setup, send PM to me....I'd be glad to help if I can.