Flood Ports were just holes. Some round, some oval, some trapezoid, it varies from class to class and, sometimes, boat to boat. But none had gratings.
Flood Valves were usually round. On a model, (when closed) they'd appear as round, recessed, blanked off holes, since they opened inward. Some Flood Valves, like the Negative and Safety Tank Flood Valves, were recessed, and would look like Flood Ports.
"The Fleet Type Submarine", put out by
www.Periscopefilm.com, should answer most, if not all, questions.
As far as the exhaust ports, I remember them as oval shaped. The shape forced the gases to blow towards the stern. I know that Pampanito, Cobia, Silversides, etc all have round ports. But, were they always round, or is it the result of many years of upkeep, and round is easier (and cheaper) to fabricate, than oval? If I ever run across a picture dating back to the old days, that clearly shows the ports, I'll accept that.
Until then, go with your gut feeling. If I find such a picture, I'll send it out.
Mike K.
