Funny, but I just ran into this with my 2GM20F. Had a little clearish, slightly oily fluid in the drip pan under the engine. I puzzled over it, even though there are only so many fluids in there--oil in the crankcase (no, this was too clean), oil in the tranny (no, this was a bit thin), antifreeze (no). Finally I thought diesel fuel, having forgotten that I use road fuel not red marine fuel. Had a slight drip where the fuel hose connects to the engine.
2000 Beneteau 331
Northern Chesapeake Bay
Ambition is a poor excuse for not having enough sense to be lazy ~ Steven Wright