Rib in Rough Water

[Maximus]

I don't think there is a definitive answer to the Original question as there are so many variables!...Like Boat...Power and performance..Kit..Crew..distance..helms experience..location ect ect.
But one thing I Do know is when it's Really Knarley out there....trying to go in ANY sort of STRAIGHT line course,and not letting the Sea dictate your passage is going to at least put you on a Hiding to nothing!...and at worse....terminate you Boating Career!

[Shafe]

Agreed. Best to take a power boat class and learn the basics. Better yet just stay out of trouble from the beginning.

[Hightower]

No ones mentioned props. In an under or lower powered boat and in rough weather I would rather gear down my prop (reduce pitch). This means there is faster throttle control/response which is particularly useful when traveling in a following Sea and needing to raise the bow quickly.

[Boatnomad]

Not used one, but have heard that the 4 bladed prop's are good for when it gets nasty.

[Jon Tallis]

As for your mate saying throttle control upwind is "totally safe" he's obviously never been out in rough weather. Nothing is totally safe. Up-sea or down-sea can both be treacherous dependant on the sea-state, capability of boat and helmsman and quite frankly - luck. That was Appledore lifeboat - handled by some of the best trained crews anywhere and they came to grief. As everyone on here has said, get some training, then get some more. Look at the weather forecast and take local advice over likely localised conditions such as overfalls etc. Gradually build your rough-water experience without risking yourself, your boat or your crew.
The sea doesn't take prisoners.