The air ambulances in the UK are outstanding. I have twice been directly involved in (non-diving) incidents the NW Air Ambulance have come out to (1st as a patient, 2nd as the first civilian at an incident). The skill at where they were able to land still amazes me to this day.
RNLI and the various independent life boat stations around the UK are also generally very good and very helpful. You might get a ticking off from either them or the coast guard if you have done something very stupid. I have had to call them out once a few years ago for a non life threatening problem requiring a tow back, post incident a couple of them came and had a chat, talked through what had happened, what could be done different and how the rescue had gone.
RNLI and the various independent life boat stations around the UK are also generally very good and very helpful. You might get a ticking off from either them or the coast guard if you have done something very stupid. I have had to call them out once a few years ago for a non life threatening problem requiring a tow back, post incident a couple of them came and had a chat, talked through what had happened, what could be done different and how the rescue had gone.