Go for it
Used my mates dagger blackwater on the Wye, Bala, did the inlets around Hayling island (semi open water) did a bit round Brownsea Island (Poole) and out down the coast towards Bournemouth. Not a sea kayak so got pretty wet from the splash but riding the swell of the waves is fuuuuuun
Would have liked to do more but he sold them trying to raise funds, i dont have anywhere to store them
I had no instruction, other than a bit at school some 20+ years ago, had a few close calls but never went under.
I'd love to take it up again