...in an actual event, you WILL be surprised, you may be injured or disoriented...and the conditions probably wont be so kind...
...At night, in the rain, in cold water. Which way is the boat?
I think I would have dual trip lines, one on each quarter, particularly for a multihull, though even on a mono a few feet can make the difference. It would be nice if the trip line were a loop, like a drogue... but then it becomes a drogue.
Would you really feel the line if you were swimming like mad, wearing foul weather gear, in the pitch dark, or would you plow right over the light trip line? Try finding a water ski rope with your eyes closed wearing heavy clothes.
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Better idea: Bring the trip line along the side of the boat, not too far above the water line. If you go over the lifeline with a tether (should have one, right?), grab the trip line, and release the tether. Would still require nerves of steel in the dark or single handed.
On my boat, I would rather the trip line was a loop, ending near the transom. Just climb uo the sugar scoop. But I'd rather use short tethers.
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Forget it.