I also have a Garmin (a Map76 model) that I like very much.
I''ll take this opportunity to share a summary of a major issue as relates to GPS navigation. A lot of the world''s charts still in current use were not prepared with the same level of positional accuracy that today''s GPS offers. The result is that you might very well know your position via GPS to within 30 feet (as an example), but the features on the chart are not represented nearly as accurately.
This uncertainty, I''m told, is made far worse with chart plotters which let you zoom in too far. Your boat''s postion may appear to be clear of any charted danger areas when in fact it is not.
Good luck with your purchase.