The RNLI is excellent. And free to use. The Royal National Lifeboat Institution also covers Ireland (pre-partition). Brits and Irish are rightly proud of that institution. They're crewed almost entirely by volunteers.Their shore launched lifeboats are also volunteers and funded by charity. Learn about the RNLI - What does RNLI stand for and more
Unlike the French version which charges a lot for recovery, so the French coastguard is always asking for passing boats to help other stranded boats - why have one stranded boat when you can have two and a real emergency.
The coastguard does have their own helicopters which handle marine rescues; typical winching recoveries. They are also free to use. As are British hypobaric chambers and medical services.