you're right--thank you for catching that. I think the idea is still sound though. there is so much loss (4m waves ≠ 3m height change; rocking motion is not up

you're right--thank you for catching that. I think the idea is still sound though. there is so much loss (4m waves ≠ 3m height change; rocking motion is not up-down motion) that these wattage numbers would in practice reduced by orders of magnitude.