The blue channel is a dive site located in the west end and is a popular dive spot for the many local dive sites. It isn't particularly hard to dive. The dive site is around 30ft deep.
The channel in its topography is complex with swim throughs and caves galore as you might work your way shallower following your divemaster. There is a north and a south wall formed on opposing sides which makes up the channel.
GPS North 16.2995127 West -86.6009067
You can get a lovely description of the swim throughs and fishes you might see on this dive from here.