depends on what you consider rough?
glass to 2 footers
lake chop, river wakes, ocean swells? all plays into this answer.
Also, depends on the lenght of boat you want
size for size cats are faster
rought water 3+ a 27 V could be good and a 27 cat could be rough Then again it all depends on how you like to drive. I know alot of boaters that like flying thier boats. I also know alot like me that dont like flying the boat through the air.
Rougher the water bigger the cat needed.
I have a 28 foot cat with about 1.5 feet of molded swim step. so I actaully consider this a 26+ cat.
I have alot of frineds with 27 and under V boats that love the ride of my cat in any waters they are used to. But I also have friends boats 30+ in lenght that i have riden and drivin and I prefer them in some of the waters we boat. Until I want the speed factor again. Then I leave the V's behind. Well at least the ones I run with
Mine is great in waters that you would take any 26-28 V in.
I do not like rough water 3+ lake chop--side to side no constant direction--can be tossed around.
Lake of the Ozarks is a great example of this.
Up to noon waters was fine. Coming out of the channel by Shooters and Back Water Jacks the waters has been labeled "Washing Machine" becasue you never know which way and how deep the holes are until you are in them.
Now this is my expereince, which is limited, I will let the big boys that have played in much larger waters then I ever have, Michigan, the Ocean etc.
They have alot more time around waht I have.
SIZE DOES MATTER