I was looking at one at Wal-Mart for about $7. It had about 50 east and west coast cities in its database and nothing on the Gulf. Huge numbers, too.

Tide Tool is a nice Palm app with over 7000 locations worldwide. There are nine locations on my bay system alone. It has currents for some passes and sun and moon rise and set times. It also can go out to any future date. For instance, I know that the Slip to Ship racers will be fighting a rising tide at 0900 on the 28th and slack for the return. Best thing is that the software is free, and with older Palms going for $20 to $40 on Ebay, it's probably the cheapest portable tide tool you could find. Aquapac makes cases for Palms, too.