I did this years ago during a trip to Cornwall. Me and my family went on a mackerel fishing tourist trap thing, you know, the strange looking guy standing near the ice cream van with a handful of leaflets, assuring you ‘the best prices on deep sea mackerel fishing!’
We had a lovely time and caught 6-8 fish, cooked most of them that night – There were soo many bones left in them it was almost inedible.

Would recommend it, but there is a lot of fish killing involved. Be prepared for blood.