Summary: I've used the Garmin 125 & 126 monochrome units for years, and found them informative and very easy to use, with the possible exception of the character limit on waypoint names. My Garmin 521s is a huge step backwards in actual usability.
Summary: Living in Hawaii I was happy to see the Garman 521s had base maps for my Island. I read the book first and was surprised to find that it was mostly about the additional G2 SD card[$275.00]. Well guess what,the so called base map is useless as a chartploter.
Summary: I ordered this unit because the advertising says it has Alaska and Hawaii base map. The map is so pixellated that it is truly useless! I have to order a bluechart card for it, to make it even functional.
Summary: I bought the S version of this. I paid a lot of money for this only to find that it has no usable map included. It advertises something called a basemap so you think that you're OK. They don't say that this map is useless.
Summary: Fungerar helt ok. Bytte från en Garmin 5010c och helt klart är denna smidigare och snabbare. Skulle dock valt en något större skärm för bättre överblick. Har vid några tillfällen tappat GPS kontakt