I planned to do some fishing yesterday aswell. The boat and the car was packed and ready to go. Weather was fine, but when i updated my loggbook on saturday evening i found out, even doublechecking, that i haven't changed oil in the Suzuki since april 22, last year....wow!
I have been fishing many hours from other boats leaving me with not even 100h on my own boat in more then one year!! The long winter was one of the reason to the few hours and the poor fishing in the Big Lakes was another.
Those occations when i have fished from my boat have been somewhat harsh and I almost knew what the oil was going to look like. When trolling in really cold water the engine works hard and the oil use to look as it's been in the engine for years, so i knew what the oil was going to look like. Black, - after just 80 hours of trolling!
I also changed the oil in the transmission. I don't buy those expensive little tubes with gearoil. I get the bigger bottles for gearboxes or transaxels. As long as it says it's Gl-4 or Gl-5 on the bottle it's fine. It should be 90 oil, but i use 80. I fish generally in cold water and 99% slow, so that's why i go with this alternative. Just to save some money and make it less messy using one big bottle instead of four small! Read your instructionbooks for enginespecification before experimenting with your engines, to see what oil to use.