I have a Garmin gpsmap 78 with a lakemaster chip and it works great for ice fishing or on a boat. I use mine year round. The Garmin marine handhelds are tough and waterproof. I just got my dad one for his birthday with the Garmin upper midwest fishing guide chip. Looking at it last night, it appears to have all the same contours as my Lakemaster chip for the lakes we fish here in MN.