That said, I'm like Woodski, pulling a boat motor is very easy (nothing complicated) if you have access to something to lift it safely.  Pulling it would let you change both the timing cover and oil pan gasket and give you a much higher chance of a leak free result.  

Yeah, if its the timing cover gasket I would certainly try it myself in the boat.  You are right, a SBC, the timing cover should go on first, then the oil pan gasket mating surface is actually on the timing cover gasket groove.  

Check out YouTube, there are some creative fellas out there that have done it.  The tough part is the room you'll have between the transom and the front of the motor.

On 8/14/2019 at 1:54 AM, wakefrankNL said:

Junior (8 yes old) taling in his forst ever faceplant. Had a slicht herdacht, but got up, shook it off and rode again.. 

Ouf... riding a board that -looks- too big for him. looks to be about 10? Did that to my cousin 15 years ago. took the board edge to the head after loading the line to a air backroll. 7 staples. Ride the right size board!

40 minutes ago, Hemmy said:

Most car dealers want your service more than the sell of the car.  They make more money on service than sales.  Can't imagine a boat would be any different.

I don't think it is an issue of whether a dealer would service a Malibu that was bought elsewhere -- it is how the jobs are prioritized when it's July 3 and everybody wants their boat fixed ASAP.

The parts or gasket set would set you back in the ball park of $50 for the pan/seals/timing cover and available from numerous suppliers.  If you have some tools, you could rent a cherry picker, bribe a couple of buddies with a case of cold beverages and do the job in a weekend.  You are about 2 hours of labor each way in pulling / replacing.  If it is truly only the front timing cover (which incorporates the front crank seal), you can do that in the boat.

Do you have any insight as to why it suddenly started to leak after your spring start up?  How much oil is it leaking?  Are you sure that the oil level is correct and not overfilled thus creating a leak?  Or even simpler, if there was an oil change, a spillage during the process?