Got an Eagle Cuda 250/300 Lowrance M56/M68 GPS/FF - Hacks :)

[peguinpower]

Found this on another site. I don't own a Lowrance so see if it works for you.

"Undocumented feature on these little GPS/FF's

In the map mode, zoom to a level where you can see navigational aids, move the cursor over one of the boxed "T"'s to display the current tide level box (that and currents are the first two nifty undocumented features).

Now press the waypoint button "wpt" and you get a detailed 24 hour tide screen for that point, on that date, including sunrise and sunset times. You can also adjust the date, time, and place, but its a lot easier to adjust the place by the cursor as the list is VERY long."

/bing