unfortunately there is no other option for diving in Praia, and when you arrive and see the city, you will know why. 🙄
Praia is not really clean and also the beaches are not recommendable to swim or to dive.
To go to Tarrafal is an option, but it is stressful, to go and return every day from Praia to Tarrafal.
I’d prefer to do other activities of leisure, like visiting interesting areas, e.g. Ribeira Grande de Santiago (“Cidade Velha”)to see the fortress and other impressive things or to go by Aluguer to the north (Serra Malagueta) for trecking.
You can also go to Tarrafal and if you stay there over night, it is more relaxing, as to return at the same day.
I wish you interesting new experiences. 🙂