(at around 34 mins) Richard was bitten in the water on his left side. When he was pulled out of the water, the wounds were on his right side.
(at around 4 mins) The "climate change" science was flawed. The ocean doesn't warm by absorbing CO2, it is warmed by solar radiant energy then absorbs CO2.
The characters are constantly breaking rule #1 for SCUBA diving... NEVER dive alone. They are regularly breaking of on their own to do their own thing while diving. This goes against the first thing anybody is taught (gets hammered into their heads) when getting certified as a SCUBA diver.