Reply #14: So tell me, do you think your uncle could have swam across currents

[ET Awful]

that were pulling him in the opposite direction (they were drifting away from the boat while the boat was also pulling away under its own power)?

Yelling will carry fairly well, but not past a 1/4 mile or so, especially with all the typical sounds of the ocean and a boat motor, the yelling would most likely have been fruitless.

The thing that would have been wise would have been having a dive light with you which could be used for signalling (a signal mirror would not have worked due to overcast conditions).

The boats they could see were both moving away, and too far for any shouting to have worked. Plus with rising and falling peaks in the water, line of sight isn't exactly conducive to spotting them either.

Your idea of swimming for the boat would likely have brought sharks even sooner than they already arrived.