July 21st, 2014, 13:34
The only times I've seen 30+ degrees roll on a Frigate/Destroyer was when the Officer of the Watch put the wheel hard over at speed to clear the weapons arcs for a simulated engagement during an air raid. That's not to say you couldn't see it in rough seas but most FF/DD have stabilisers to reduce the roll amplitude anyway as it improves the effectiveness of the weapons systems.
I hate to think what 30 degrees of pitch would do to the ship!
I can't find my copy of the deck limits for operating the Lynx, but the sloping ground limit for landing was only around 10 degrees anyway so you wouldn't want the ship rolling more than that.