rude awakening for anyone out there on something less than 6' unless you are only 5'4". In my opinion. But I've been wrong in the past I just don't see how a cat 4 is going to only generate head high surf.
The power of the wave itself, not just the height. is going to require a bigger board.
Nut up, dudes. I just got back from a trip to costa rica where i cought 12 foot pavones on an epic south swell. you know what i rode? a 6'5 pin tail. Im 6' and like a 185 lbs or so and got some killer waves. Sure there were guys out on full on guns, but they got the same waves as me and had to make bigger, slower turns. When is pumping, as long as you can get into one, your just planing on the last couple feet of your stick anyhow. Id say more important than size is tail shape. Get something fast and responsive. The fish might be fun, but i find it a little loose in bigger, sketchier days.
Take the board that you have been ripping little waves on - grab your junk - and get tubed! Big waves are what its all about. There are finally some on the way, not a good time to break out your skirts.
Sure sometimes having the right board can make a difference, but I am reminded of a story my buddy told me about a trip to Indo a few years back. Boat trip and he was solo and didn't know anyone. Some dude gets on the boat with a pink soft top fun board and a bunch of young dudes from the states start laughing at him (my buddy is from south america and doesn't care to judge anyone). When it came time to charge guess who got it. Turns out if you can charge you can do so on a pink soft top fun board. My buddy said the boys from the states were only good at drinking, being annoying and hooting up waves.
I agree with a previous post, grab what your comfortable on, get mentally ready and charge.