If you have noticed that your engine is running a bit hotter than usual it may be time to check the heat exchanger. I have had a run on heat exchanger services these past several months.
Of course this may be a backlash from the lack of boating over the last several years.
It may also be that the heat exchanger is an easily overlooked piece of equipment.
The calcium build-up is clogging the tubes of the exchanger and takes that tube out of the system to do any cooling of the coolant or oil. Lose enough and you get overheating by lack of heat transfer, or raw water pump failure due to restriction in the raw water system.
If you think it has been a few seasons since the exchanger has been checked, CHECK IT !!!