They should call stand-up paddle “stupid paddle”, because it is stupid-simple: you stand on the extra wide and long surfboard and paddle out to sea, checking out places you normally can’t (boats aren’t allowed close to the beach, for swimmers’ safety).
The best part is that you can rent a SUP board and oar for R$60 an hour, which is the maximum amount of fun one can have on the board. This is a sport for anyone from 8 to 80 and that several people can do at the same time. You can rent one near Posto 6 in Copacabana (all the way to the right of Copa, when looking out to sea).
Eco Clube SUP Posto 6, Copa (near Rua Rainha Elizabeth, on the sand). firstname.lastname@example.org Price: R$50 for SUP equipment, R$10 for lesson. Pay R$40 for either equip or equip and lesson.