Robbie,
Glad to hear that you are making progress. i can tell you for an absolute certainty that my 2000 Epic will not shut down when the oil pressure reading goes to zero. Many of us have experienced problems with our oil pressure senders, I have been through four of them. Mine recently failed, it goes from zero to full scale while driving. There is only one sender that I know of, it is on the oil filter mount.
Is the engine installed in the boat? One common problem that causes similar symptoms is the dead man switch by the driver. Make sure it is adjusted properly or bypass it for testing.