the islands are a diving hotspot due to comfortable water temperatures, the wide variety of marine life found there and their proximity to the mainland.

underwater visibility is generally very good, though it is diminished during low tide as a result of outflows from the joatinga canal, located between são conrado and barra da tijuca.  

one thing to keep in mind when planning a diving expedition to the tijuca is that though they are very close to the shore, most tour operators disembark from guanabara bay, which greatly lengthens the journey - anywhere between 40 minutes and 2.5 hours, depending on the type of boat.