ShotOne, Buccaneers would routinely fly at 420 kts at 100 ft asl with reference to the radalt. On accelerating to 550 (plus) knots, the baro alt would be matched to the radalt so that when entering a 4G turn with the radalt now unlocked, 100 ft asl could be monitored and called by the back-seater. In a glassy sea state, the baro alt, and the nav's monitoring of it, was absolutely vital to support accurate and safe height keeping in a high G turn.