Where is this boat registration?

I’ve found an old photograph and I’m trying to work out where it was taken. It’s a harbour in a sunny place with palm trees, I think it’s probably in the Med somewhere.

There are two boats that have id numbers on them that say “PM-1-867-92” and “PM-1-387-1982”. Does this mean anything to anyone? I’m guessing the “PM” might mean Palma (in Mallorca)?