Hi Gunnar,
That is the mystery, certainly was not 937. Could be 938, 939. Have now already certitude about that. But think it is 938. It looks indeed like FF33 but was not certain because of the type. Haven't seen other pictures of an L model.
It certainly was out of service before half October 1917 !
So the accident must have occured between 15 May and 17 October 1917.
Looking at the damage I think it was brought in by a ship to the Zeebrugge Mole. Half of the right float is missing. Left float is broken in two also.
This should give us a better base I hope to find out what happend.
Thanks and best from Regulus