[Euro Cruiser]

"Fresh water cooling, where fresh water goes through a heat exchanger of coils underneath the boat, and is pumped up to cool the compressor."

Just for clarity's sake, let's make it clear to thread readers that there is no direct link between the choice of using fresh water to cool the compressor of a reefer system and a single specific method for how the fresh water is sourced. The latter depends on the design of the reefer system if equipped with water cooling.

'coils underneath the boat' means little to me, but most water cooling coils (thru which freon lines are routed) have in the past been mounted directly onboard the reefer platform. It's a relatively new concept to have the water cooling line run off the platform to a remote site (thru-hull or external cooler) and back. Whether this is 'better' or not is IMO more dependent on the locations of the water sources (fresh and raw) on a given boat and one's subjective preferences. I surely saw no inherent benefits in putting another hole in my boat when instead all I had to do was add a few feet of vinyl tubing and 2 'T's to the plumbing in one of my water tanks.

Jack