A few tidbits about VUCC. Out of the 32,400 4-digit maidenhead grid squares in the world, the highest claimed and approved by ARRL is 1,700. They all count, no matter if they are land, wet grids, or guess you can call 'em slick grids for ice. Operation is possible from 1, 2, 3, or 4 grid squares simultaneously. Just be on the border or intersection and provide evidence as required in the rules. For FFMW, there's 488 grids in the lower 48 states. Grids we share with Canada and Mexico count for FFMW, even if the operator isn't in the US when the contact is made. The number of ops having all 488 approved were low a few years ago, but has grown to 40 as of today.
Hoping to add to my VUCC count this summer for DX and FFMW. Already worked 7 new grids in Argentina, Brazil, Chile, and Peru with recent openings, and 4 have been confirmed.