A Martin PBM Mariner's crew scrambles in response to a SAR call. The late-1940s and early 1950s were the heyday of large seaplanes. The service's best known seaplane pilot was Captain Donald MacDiarmid, who was a fanatical advocate of the seaplane's capabilities. Noted historian and retired Navy/Coast Guard aviator LCDR Barrett Thomas Beard described him as a "nearly fictional character within the ranks of the Coast Guard and the Navy in his lifetime."