what else is wet?
we can assume the engine is low (if not the lowest) in the boat which mean;
1. a thru hull
is leaking elsewhere and the water is running to the low spot in which case you should see / feel water fore or aft
2. the leak is around the engine.
is the water returning since pumping it out?
try an OLD trick for identifying which valve is leaking... buy a multi food
coloring pack and squirt a different color on each thru hull
. when the water pools it will have a tint and point u to the culprit.
if (for example) everything aft of the motor
is dry you can ignore those thru hulls.