That, right there, is number one. The ocean is a powerful creature.
I understand the fact that water-filled footgear isn't going to "drag you under".
However, the ballast that water-filled footgear creates makes it much more difficult to keep your head above the surface, because your center-of-gravity is changed.
In rough seas, that "theory of relativity" makes it all the more difficult to maintain and sustain your bouyancy and at the same time, battle the elements (wind, water, waves, current, precipitation, whatever).
In the years when I was on Kodiak and the Gulf of Alaska I wore hipboots when motoring clients and myself via skiff to hunting spots. Didn't like it too much, but I chose to do it.
Luckily, I never ended up in the water. Caution and wise decisions prevented that from ever happening.
