Fix for ferry boats on Rio-Antirio scenery for P3Dv4 2017-10-14

This is a fix for boats going funky in waves in P3D v4.x in my scenery of Rio-Antirio bridge. Thanks to Henrik Nielsen and his tester Knud for helping me solve the cause. The ferrys used to have platforms and you could land helis on their decks. apparently these are very close to the water surface and waves touch them making the ships move funny. the platforms are now gone so no stunts are now possible.