my paddling ‘history’ confirms many of the comments above, adds one or 2 new ones.
My 1st ‘seakayak’ was a large cockpit Aquaterra Chinook.
- a bit difficult to roll.
2nd was a Valley Nordkapp (prior to large cockpit Valleys).
- seaworthy, ‘connected’ to boat, much easier to roll.
- However, on very long paddles, I needed to bend my knees - not possible in an OC boat.
I started carrying a paddle float, and (while at sea) would occasionally create an ‘outrigger’ with it and the paddle, so I could ‘climb out’ and sit on the combing, pull the legs out to stretch.
about this time, I picked up a 2nd hand Prijon T-Slalom ww boat. (did some ‘light’ whitewater paddling in WI and MN). I think it was Prijon that came out with the 1st ‘keyhole’ design. An ‘excellent’ keyhole - could really get ‘locked’ into the boat.
3rd seakayak was a Valley Nordkapp with large cockpit (when they came out).
AWFUL. Difficult to roll (large cockpit). They came out with a little ‘flange’ that could be installed soon after - didn’t help much.
I took a long trip overseas in a Caffyn designed ‘Arctic Raider’ (OC). Very seaworthy, full contact with boat, but banged up the shins on many a surf landing.
After returning to states, went to a ‘Bean’ symposium in Maine ('93). Nigel Dennis was showing his newly designed ‘Romany’. I discovered the ‘seaworthness’ (rolling, handing heavy seas, etc.) at a later point, but what hit me first was the ‘real’ keyhole design (not just a little ‘flange’ that most of the other folks were putting in their boats).
Paddled the Romany and Explorer for many years and in some nasty stuff - never ‘pulled’ out of boat, and could stay at sea all day.
Nowadays, I mostly paddle lightweight boats (eg: Sterling’s) (Brit’s typically build them extremely sea-worthy - but also very heavy)
If I won’t be at sea for more than a few hours, I like to paddle the Tahe Greenland (OC). (again - my knees need to bend after a few hours)