Hallo Washout.

In het boek "Martin Aircraft 1909-1960" van John R. Breihan/Stan Piet/Roger S. Mason uit 1995, ISBN 0-913322-03-2 staat op blz. 186 het volgende over de Seamaster:
Its payload was carried in a rotary bomb bay, pneumatically sealed to be watertight.

Op blz. 194:
Conventional and "special-weapon" (nuclear) practice shapes were successfully dropped from the rotary bomb bay, and night and day photo-reconnaissance pods were also tested.

The production planes were also equipped with midair refueling probes, and "buddy-pack" kits were designed to fit inside the bomb bays, allowing fast conversion into tankers for refueling other aircraft.

En op blz. 196 staat als bijschrift van dezelfde opname als door mij geplaatst het volgende:
P6M-2, 145878, shows in-flight refueling pack mounted in rotary mine door.

Mvg, Ruud.