We've loved swimming, from the first time I took dd at 8 weeks, we now go most weeks.
My lo took to it straight away, my friend's baby hated it, but after several progressively deeper baths, and bringing her home bath toy with her, she likes it now. These might be worth trying.
It might make it easier the first time to wear your swimming costume under your clothes, I don't now, but it's not easy to start with. Take a spare swimming nappy - you just never do know!
My dd ALWAYS wants a feed and crashes out stright afterwards. I have my route to the cafe well planned!
If you have more than one child, or aren't keen on the water yourself, one of those flotation things is very very useful. Otherwise, I don't think they're really necessary.
Any use???