Hi
I use a garmin 76map. works well enough. easy to use and such. can also get tides in the US.
I;ve had two. one had a little corrosion around the pins on back but since I don't plug in
much it still works. the other didnt work when I went to use it so I sent it to Garmin and
they replaced it. its worked fine now for 3 years. uses 2 AAs but I can't say for sure how long
they last. around 8 hours maybe? I usually turn it on and off.
hope this helps.
Rickf