Look very easy to work on this engine!

Your videos are very helpful, thank you! I have my boat in water all year thanks to the climate and regular use. But it's saltwater. What should I do regularly (besides the yearly professional inspections of course) and what should I keep an eye on? I do oil checks before every start and look at the motor. But I don't really know what exactly to look for and what parts need special treatment in between. (Can't really do anything on the drive because it's under water.)