I had a tide watch, I think it was rip curl, and it was quite good. You set it to the high tide of your chosen port, and away you go. It could have done with a secondary port as well though.
I have since had casio tide watches. They are ok, but in order to set them you have to input lunetidal data, which you have to search for on t`internet.
Less handy if you want to check a new location when you are out and about.
I am seriously considering this software myself, I dont know about wap pushes though. I would rather have a file that I could download then transfer to my phone.