Multi directional swell is a bitch aint it
Especially when coming at 30-45* off your heading.
I paddled ski in small water for a year before coming to the ocean and I agree - even though I would chase down the nastiest boat wakes I could find and was comfortable in any conditions small water could throw at me, the ocean is a whole 'nother animal. Ground swell, plus secondary swell, plus wind swell, plus reflected waves all make for quite the difference in stability.
Towards the end of your paddle, did you sort of get the feel of the waves down? I mean, i think to be successful in messy conditions your bottom half needs to just roll with the waves. What your torso is doing (paddling) is more or less disconnected from your lower half (balancing). Yes, you're transmitting power through your legs and rotating, but its like sitting on a Swiss ball while doing something else.
If you're used to Chesapeake bay in messy stuff, you think it was the fast moving ground swell that caught you off guard? Typically I find if you're ok in steep wind chop, the ground swell isnt too bad, but I suppose it can combine and get more peaky and also reflect more.
Anyways, glad you got to experience a proper ocean race! messy, multi directional swell can be a beast. The CA coast can get some nasty conditions starting this time if year.