Sea Creatures and Tides/Currents

it mustn't be easy swimming against the tide redemption, although some maybe unaware of it

It is no more difficult to swim against a tide than with it, unless you assess progress "over the ground", relative to some fixed point.

If you go offshore in a boat, and there is no wind, the motor is turned off, but the GPS says you are travelling at 2 knots, that would be the speed of the current, relative to the sea bottom. If you jumped out of the boat, and tread water, you would not move relative to the boat.

I knew a bloke who thought his speedboat got on the plane quicker, running downstream with the river flow, but upstream would struggle. If anything, it would have planed more readily going against the current, because the air resistance would have been lower. Speed through the water, versus speed over ground (SOG) confuses some.

Of course sea conditions create different circumstances, I think the bloke who thought his boat planed sooner running downstream, was fooled by the trees on the riverbank going past more quickly. I recall in the 1974 flood in the Brisbane River, a big tug was barely able to make headway upstream, it was under full steam, but you could have made a cup of tea and came back to have another look, and it seemed not to have advanced much upstream. Had he turned around and headed the other way, he'd have looked like a speedboat, from the point of view of an observer on the bank.

Just thank God there are no currents in the swamp that Donald is draining.