If you decide to spend more days with Hotel MiraBela than just the three days of lessons, they can arrange the best excursion on the island, being an organized island tour. They can also arrange any other excursion or activity for you, based on your preferences (or maybe on a no-wind day), like horseback riding, sailing, car or quad rental, a day trip to Boa Vista, or anything else.
Diving
Cape Verde has some nice dive spots, including wreck dives. It is not like diving in Egypt, but you can make some really nice dives here, comparable to diving in the Caribbean.
Quad or car rental
Doing a quad tour is a fun way to explore the island. You could even do the full-day island tour on a quad. The standard island tour of course is fully organised, but this may be more fun for some. They can give you directions so you will not get lost. There is a place in Santa Maria where they rent out quads with a big backrest. With two persons on one quad, this is a lot more comfortable. Cars can be rented in many categories for reasonable prices.
Turtle tours
From mid-June to late September, it is possible to go on a tour to see the big turtles lay eggs on the beach. This is done at night. The tour guide drives you to a beach where they search for the turtles to come on land. Since it is wildlife they cannot guarantee that you will see it happening, but 99% of the time you will be a witness of this impressive event. From late July until mid-October, the baby turtles hedge in various places on the island. It is very cute to see this happen and see the little ones crawl out of the nest. This happens in different places each year, so ask them where you can go to the best and they will find out for you.