.... We towed a swimmer on a lifejacket harness at various speeds and found that at speeds over 4 knots the swimmer can barely keep his/her head above water. At six to eight knots the bow wave created by the person came over his head and he had great difficulty breathing (we stopped the test at this point!). At this same speed the drag of a person in foul weather gear is so high that two crew could not drag that person up to the boat and out of the water. When a boat is sailing at twelve to sixteen knots, it will be almost impossible to get a person back aboard. This leads to two conclusions, first, use lifejackets without a harnesses for high speed sailing or end jacklines far enough forward that, should a person go overboard, they can still hold onto the rail. If they end up a full tether length behind the boat, they may be drowned before the boat can be stopped.
This scenario does not sound logical. If there are crew members still on the boat, they would not be trying to retrieve a dragging man with the boat still going at speed. Wouldn't they immediately stop the boat?
The main danger would be if you are the ONLY person on the boat and you fall overboard and are being dragged and have no way of stopping the boat.
I do like the idea of having the tether anchored far enough forward so that if you fall off, you are still alongside the boat and can maybe hold onto a footstrap or push over the tiller to round the boat up or make it capsize or whatever, in order to stop it.
