Comparing 2012 Garmin 5" screen GPS units

[Sonosailor]

Our old B&W Garmin is slowly collecting lines across its little screen, and it is time for a new unit. Love that the new units have built-in antennas. The existing unit is sitting inside at the nav station, and the steering station on Cat Tales, 35' Fountaine Pajot, does not have much space for a permanent unit.

So, I'm thinking I'd like one of the 5" screen Garmins that I can attach to a mount and plug in to power (only) at the steering station when travelling, and disconnect and safely stow when at anchor. Wife wants AIS compatibility for some time in the future, but likely the technology will change again before we make that jump. I've looked at the literature, and they all sound the same (I feel like a dufus reading the specs). Any recommendations or fresh insights into these units? 546, 536, 526, 541, 531, 521? Any comments about similar competitors' units?

[stevensuf]

i bought the little 451 unit, perfectly usable, hooked it up with ais, very handy

[Tom.B]

IIRC, the difference between model numbers usually has to do with which chart package the unit has onboard... if any. Base map, inland, US & Bahamas, world, etc.

[Sonosailor]

I thank you for your comments. After your words about the relationship between models and basemap systems, I got the drift about these, and could understand their models and charts. Actually, however, we've decided to give the industry a couple more years to evolve, especially as AIS keeps getting to be more of an option in some products. Instead, we purchased an iPad2, the version with WiFi plus 3G, which has the built-in GPS receiver. We installed the iNavX software, and went with Navionics charts for the Caribbean. It isn't on the boat yet, but looks and works soooo fine.

We'll watch the old Garmin slowly fail while we enjoy this option, and keep watching the technology evolve.