I apologize Marin, Missed my mark.
No you didn't. Your points should be paid attention to by everybody. An awful lot of people on the water don't seem understand what it does and why.
Growing up in Hawaii, every year there seemed to be several people killed by the ocean. Very often these were servicemen who had grown up nowhere near the ocean and being in Hawaii was their first exposure to it. But a fair number were locals who should have known better.
These people were not killed by falling off boats out at sea or bitten in half by sharks. Most of them were killed right on or very close to the beach, pounded into unconsciousness and being drowned by the waves while body surfing in the shore break, smashed into the coral seabed by waves just offshore, or sucked and held under by wave backwash that pounded the air out of them.
It's just water, right? How strong can it be? That, I think, was the attitude and it nailed people every year.
The situation set up in the first post in this thread describes what seem to be very benign circumstances. Anchored, dark, cold water, a little bit choppy, and a mild current. Boaters have died in less.
The people getting smashed into the beach and coral or sucked under and held in Hawaii were mostly younger folks, teens to thirties. The people who buy the kinds of boats most of us in this forum have tend to be much older simply because it can take a fair number of years of earning to eventually afford something like this. And what happens to most people as they age? They become more susceptible to all sorts of things. A fall into 50 degree water that might momentarily stun a young person could stop the heart of an older person.
A broken wrist that might inconvenience a younger person but wouldn't stop him/her because of the strength in the other arm could prevent an older person from getting out of the water because he/she simply be too weak with one arm or hand to do it.
As a kid--- perhaps I was eight or nine-- I got caught in the backwash of the shorebreak at Makaha which at the time had a pretty steep slope to the beach. I wasn't even in the water. I was just standing there and the wave arced up, smashed down, raced up the slope, knocked me off my feet, and hauled me back down the slope so fast I didn't even know what was happening. I was completely powerless to slow my slide, stand up, or anything. I was terrified to say the least.
Would I have drowned? I don't know. Probably not. I never had a chance to find out as the submarine commander my mother was dating at the time who was totally at home in the water and was an expert surfer, ran down the slope and hauled me bodily out of the water and carried me back up the slope.
I was not scared away from the ocean by this incident, and all the years I lived there I had no fear of swimming in it or boating on it. But I never forgot that immense power that dragged me down the beach, power that no way in hell could I ever overcome either as a little kid or as an adult.
So your points about current and being aware of it and learning to work with it instead of against it is solid advice that should be heeded by anyone who has anything to do with the ocean, even our "benign" inside waters. Because when the current cranks up, they are not so benign.
The two photos below are of the same rapids in BC. The waves are standing waves--- they don't go anywhere, they just keep breaking right where they are which is why the kayakers and surfers love them. Keep in mind that this caused simply by the change in the tide. I mean, how big a deal can that be, right? It's just the tide for Christ's sake.
This happens in both directions four times a day. At slack, it's dead flat calm. For about five or ten minutes.......
I've flown over it a lot in the floatplane and seen it like this from the air. But I've never been next to it or heard it. I understand it sounds like a train going by about ten feet from your head.