For the last several years a blue motor catamaran has been patrolling the Arenal beach. It has dark blue hulls, about 6 metres long, and 3 meters beam, with a white wheelhouse amidships. It is called Mini Pelican II and appears to be registered to Medio Ambiante. What is strange is that in front of the wheel house, between the hulls, is a scoop or shovel which can be lowered into the water.
Some time ago it lowered this scoop and shortly afterwards a boat turned up with three scuba divers who went down and had a look. As far as I am aware, it only patrols the town beach, and has Medio Ambiante markings