Photos: PBY-1
3-P-10 (appears to be BuNo 0152)
Circa 1937

These planes are from VP-3F. I believe the "F" indicates that this squadron was assigned to the converted seaplane tender USS Langley, making this a sister squadron to VP-6F.

(Photo from the R.L.Lawson collection, courtesy of the Nat'l Museum of Naval Aviation)