Here is what I found in connection with the abbreviation "Flbt" (Flugboot / flying boat):
Hansa-Brandenburg CC --- 35 aircraft was/were delivered
Hansa-Brandenburg FB (CFT) --- 6 aircraft was/were delivered
Hansa-Brandenburg W.18 --- 1 aircraft was/were delivered
Hansa-Brandenburg W.20 --- 3 aircraft was/were delivered
Oertz W.4 --- 2 aircraft was/were delivered
Oertz C (W.5) --- 5 aircraft was/were delivered
Oertz G (W.6) --- 1 aircraft was/were delivered
Oertz C (W.7) --- 2 aircraft was/were delivered
Oertz C (W.8) --- 1 aircraft was/were delivered
Oertz FB 3 --- 1 aircraft was/were delivered
Grigorowitsch M.9 --- 2 aircraft was/were delivered (captured aircraft)
Sopwith Bat Boat II --- 1 aircraft was/were delivered (bought in 1914)
AEG F.I --- 1 aircraft was/were delivered
Curtiss F --- 2 aircraft was/were delivered (bought in 1914)
Friedrichshafen FF 11 --- ? aircraft was/were delivered
Lohner L --- 2 aircraft was/were delivered
Rumpler 4E --- 1 aircraft was/were delivered
Dornier Rs.II --- 1 aircraft was/were delivered
Dornier Rs.III --- 1 aircraft was/were delivered
Dornier Rs.IV --- 1 aircraft was/were delivered
This results in only about 70 flying boats used by the Germans.
Hope this helps a bit ...