Another thing to consider. Engine Nut, who works for Indmar, once posted here that the reason Indmar called for 89 octane was due to the fact that most people use their boats infrequently. 87 octane is fine, but 86 is not. So, to avoid having people fill up with 87, then leave the boat sitting for a month or two between uses and starting it up with what was no longer 87 octane fuel, Indmar recommended 89 octane so that there would be a little buffer for less frequent users.
I think it is a good idea to stabilize any fuel you don't intend to burn off in the next two weeks before that last outing of the weekend.
Previous: 1993 Prostar 205
Red 1998 Ski Nautique, PCM GT40, 310 hp, , Acme 4 blade, Perfect Pass SG/Zbox.
Be kind. Have fun.