I have paddled literally thousands of miles using the Garmin 7* series. The older gray scale 76 is great the color one rocks.
There are some issues with the 7* series. First is that the
battery cover while good in a sailboat or a
single day use on a
kayak, will allow
water in after 3-4 days of hard kayaking. This can be mitigated by smearing dielectric grease on the lip of the
battery cover to enhance its waterproof rating. The same for the data
ports.
Finally, in zero visibility you MUST have a magnetic
compass. I discovered the hard way in the middle of the night while fighting an outgoing tide that there is a lag on the
compass. FWIW, I would carry a
cheap compass in my
kayak PFD as a backup, just like you have a compass mounted on a sailboat
Bill