gotta say tumor id like to see this aircraft added along with several other sea planes but as they can hardly be used for dogfighting I think they would need some sort of role before they are added.
My thoughts on this was :
A) used as a specialist artillery spotter: pilot of seaplane and the ships artillery gunner have a .join command which then makes the artillery shells appear a different colour for the seaplane pilot.The sea plane pilot can then direct fire visually for the ships guns.(the colour helps players differentiate shells which at the moment makes this sort of thing very hard to do).
b) The seaplane can 'mark' a point on the map which feeds the exact coordinates into the artillery gunners computer.
c) seaplane acts as a mobile radar illuminating any enemy fleet nearby allowing rest of country to see its position.
all are a little bit weak as roles but what else is there?

apart from maybe having depth charges or mines carried and dropped which would be cool for when we do get subs etc and cool for trying to catch fleets without facing that AA fire.
there are loads of seaplanes on all sides which would be cool for this sort of thing. especially if they have to land on the water to lay mines etc.