Thirties Swimsuit or Trunks
For men during the late thirties and early forties trunks took over from regulation swimsuits.
It is not unusual to see snapshots of youths wearing regulation swimsuits turned so that he appears to be wearing trunks.
I surmise that most men would have bought bathing trunks as these came into fashion although I have observed they were worn very high at the waist to cover the navel.
This obsession with concealing the navel applied to both sexes.
The war spelled the end of regulation swimsuits for men.
Younger brothers left with hand-me-down regulation costumes seemed unwilling to be photographed unless they tucked the singlet top into the waistband.
This gave the appearance of swimming trunks.
Photograph Remington South Devon
Dated on back Frid 18.8.39