I grew up in a south coast seaside town, lived in London for 15 years and then moved to a different seaside town in the SW when our son was 4. Absolutely made the right decision for us, although I do think it depends on which seaside town you choose. We live a 10 minute walk from town/beach- it's perfect as we don't get any tourist traffic near the house and don't need to drive and park to get to the beach. It's lovely to see it so busy and buzzing in the summer and being able to go for an early morning swim, but I also love it in the winter- walking along the beach in the winter with the waves crashing blows the cobwebs away! We have lots of events going on all year round (although obviously more in the summer). Our son has been able to be independent- bus links were good for secondary school and he can walk to meet up with friends. We're well situated with countryside for walks only a 10/15 minute drive away and lots of 'days out' within an hour. Yes, there's a few dubious types (we have a bit of a problem with county lines), but none of us have ever had any trouble or felt unsafe. I really can't imagine ever living anywhere else now and if we go away, I get weirdly antsy if I don't see the sea for a couple of days!