Thanks, yes Martin built a scaled originaly 1/2 then modified 3/8 of the Mariner, the model was nicknamed "Tadpole clipper" had 1x120hp engine driving (via belts) 2 propellers, it flew a bit but then belts kept on breaking so was only used for hydro research which was what they were interested in in the first place, aerodynamics can do better in a wind tunnel...
It has been restored in 1987 and is in a museum.. all this comes from the museum website..