20 Dollars Carlos Viegas Gago Coutinho

Gago Coutinho was the Portuguese naval officer and navigator who, alongside Sacadura Cabral, completed the first aerial crossing of the South Atlantic in 1922 — a feat that required Coutinho's own invention, a modified sextant adapted for use in aircraft. Liberia's commemorative program in the early 2000s issued dozens of silver pieces honoring aviators and explorers with no direct connection to the country, a commercially driven series aimed squarely at the collector market rather than circulation.