BLUEMOMENT

Do I change it now or before we go back in.
The magazines say now to reduce acidic deposits but my cousin the agricultural contractor says that he always does his foragers at the beginning of the season.

My vote would be for - do it now.

Check level and condition at the beginning of the season to ensure that you don't have any slow ongoing problems like water or diesel leaking into the sump - which wouldn't be obvious when the oil is being heated up on a regular basis. Either just look at the dipstick or even better draw a small sample from the sump into a clear jar using your oil change pump.

Ash

I was always advised to do it when the boat came out the water.

It means that nasty stuff doesn't sit in the sump for 6 months.

Donald

Another vote for do it now. (I've just done mine despite the starter hiatus - of which, more elsewhere.) Ideally, the last sail (motor) of the year to get it all heated and stirred up then do the change on arrival. A quick run again to get the oil into the filter and check level - quite difficult to see as the oil is all nice, clean and transparent!

Checking that the level is still the same some months later makes a lot of sense too.