Island cruising

We went out to Espiritu Santo Island Marine Park for 4 nights. It is an easy day from La Paz to the first anchorage on the island where we did a bit of snorkeling and walking the beach looking for shells. . We saw some manta rays, whales and many different types of fish.
We moved to a different anchorage each night and did some short hikes up the nearby hills which are covered in cactus plants of every type, beautiful to look at but you don't want to touch them. A couple of black rabbits surprised us when they jumped out of the bushes, they seem to be running wild on the islands. We went to the very north end of the island where there is some famous rocks called Isla Los Islotes. They have a sea lion colony and tour boats come here bringing snorklers and divers to swim with the sea lions. We went out there early in the morning before the wind came up and while I looked after the boat, Dorothy rowed the dinghy to a mooring line and went snorkling, the sea lions would swim right up to her face and vear off at last second. Dorothy was on a high after that, she said it was the best snorkling of the trip, lots of coral, fish and wild/exciting sea lions.
Last night the wind came around to the West after dark and sent a large swell into the anchorage and I got ready to head out to sea if it got any worse. But by about 2 am it died down and I could relax and go to sleep, rather then catnaping. Then around 7am the wind came up again more from the wsw and we decided to head back to La Paz a day early. We had a nice close hauled sail most of the way back. As we neared the channel we say a whale nearby and then it stuck its tail up in air and slammed it down on water with a loud bang and splash, and then it did it again and again for 15 or 20 times every few seconds. Anybody know why? We then went to Marina Palmira this time so we would see a different part of town, good rates too. Will stay here for at least 5 days over Chriistmas and then head North again if we are ready. Hope everbody has a good Christmas, Feliz Navidad.