I've had a few different ones, and I use them routinely. I find them most useful for a quick check of which beach is most likely to be working (I have a
lot of options) and also, while Im out in the surf, I'll often check the tide to see whether the conditions are likely to improve or not.
I had a RipCurl which was pretty good, very easy to read at just a glance. Eventually the strap broke and I haven't got round to fixing it, but it lasted years.
Currently got a Nixon one - the watch is great, but the instructions that come with it are dreadful, so there have been a couple of moments when I couldn't work something out or I thought it had gone wrong.
The Nixon one tells you (roughly) the height of the tide as well as the time, which is pretty useful.
Gimmick? Possibly - you could just look it up, and there's not a lot of point in knowing if you're going anyway, but I find them useful
