Check out these cliff dive images:
The entrance of lagoon of the Gate of Hell – Anse Bertrand
Image by Polar lights
From the beach to the entrance of the lagoon, the tidal current is very strong, and when you arrive at this part of the lagoon, the entrance, you’re in a big big swirl!
Funny at the beginning but very tiring swimming, even if you dive to seabed.
But, otherwise, nice place for snorkeling.