Two divers swim past a moon sponge, on the North side of Santa Cruz.
Swimming into a stiff current isn't much fun, and if the scenery is boring it may not be very entertaining either.
Sometimes dive training gets a little serious in the Blue Hole, as divers do fin pivots on squares of PVC pipe suspended at 40 ft, or practice compass navigation within the confines of the sinkhole.
Diver in low visibility. A light can help, although it can also simply illuminate whatever is blocking the view to begin with.