Why sea state 10 demands self-righting rescue craft

What does sea state 10 feel like for a surface vessel?

It is extreme weather that can bury ordinary surface craft in water, so rescue boats expected to operate there rely on self-righting designs that recover after capsize.

The panel describes sea state 10 as weather that can make a surface vessel behave more like a submarine. Ordinary ships should avoid such conditions, but rescue services may still have to go out. Their boats therefore use hull and stability arrangements intended to roll upright again after capsize. The comparison explains why rescue-craft design differs from normal small-ship design.