>Всё-таки PT Gunboats - это паллиатив. PGMs были и крупнее, и именно артиллерийские корабли, "канонерки" как есть.
про спецпостройку
All eight PGM-1s were converted from SC-497-class submarine chasers.
All 24 PGM-9s were converted from PC-461-class submarine chasers while still under construction.