Work party L3.JPG | Gwulo: Old Hong Kong

Work party L3.JPG

Work party L3.JPG

I can only speculate what is happening here, but maybe a submarine expert can offer an opinion. Are the three officers standing on the keel of L3? It looks as if some sort of inspection for damage is going on.
 

Date picture taken (may be approximate): 
Tuesday, January 1, 1929