There are a number of islands in the archipelago with Sal and Boa vista being the ones being developed for mass tourism Sal is more developed than Boa Vista however do not expect either to be simmilar to Eurpean resorts most of the new hotels are self contained and A.I. outside it is Third World not a place for clubbing or shopping . Sal is a bit more developed than Boa both have fantastic beaches and Boa has the best. The island are on the same latitude as the Southern Caribbean so get good weather all year being in the Atlantic they can get some strong winds and cloud but you will need high factor sun protection they have little rain September generally the rainy season. My videos may or may not help.

Further to Nicks post, the sea can be particularly rough sometimes so it is common for the red flag to be flying on beaches in front of All Inclusive resorts. There are a limited number of things to see on the islands, dont expect to hire a car and go it alone, your hotel may be a long way from civilization so you tend to either stay in the hotel resort and enjoy the guaranteed sunshine or go on an organised excursion.

Just returned from Sal here a re a couple of short videos.
Big waves at the Blue Eye and Swimming with Lemon Sharks

Looks amazing. Unfortunately circumstances changed shortly after my posting and any holiday is now on the back burner for the time being. Hoping to be able to resume travelling by the end of the year but suspect it could be next year.