As seen here, seaplanes have these, or they'd be at the bottom of the sea
The helicopter would have been rightly seen as never equaling the 313 mph... [DOC] [TLE] seaplane | aircraft | Britannica.com [PAR] Click here to search ... A seaplane must have sufficient buoyancy to float on water 
and must also have some means for supporting its weight ... Ways of meeting 
these requirements were provided by Curtiss in two forms.