Trying to build a "Sailing Boat"

[oh016]

I wanted to build a craft in the form of the small expedition boats the sea-faring people of the south pacific used to discover new islands.
V02 was my first success - very fast but tricky to steer as it was really behaving like a boat cut out of a log - rolling and swinging during speed and/or direction changes.
http://steamcommunity.com/sharedfiles/filedetails/?id=1249285965
Finally arrived at V04 which is a stable sailor and still reaches a good speed.
http://steamcommunity.com/sharedfiles/filedetails/?id=1249287373
http://steamcommunity.com/sharedfiles/filedetails/?id=1249288604
But all versions I tried - irrespective of numbers of blades added - had the same problem: They worked very well as long as I only left and re-entered the cockpit or saved the game. But after Save and Reload they ended as U-Boats, blades working at max speed but no rising possible. Probably connected with the problem/bug of resetting max flight height to ground level that my gaming partner and I have observed with other blade driven crafts and never could find out why some were affected and others not.
http://steamcommunity.com/sharedfiles/filedetails/?id=1249290018
Until this problem is analyzed and explained or solved there is only one solution for my sailing boats: To add hover pads.
http://steamcommunity.com/sharedfiles/filedetails/?id=1249291852
Unluckily this reduces speed by a considerable amount, they do not behave as well like "sail" driven boats as the original forms (too fixed in horizontal balance for my taste) and it also spoils the form I had in mind - but at least they do not sink every time I reload a save game. Only advantage: I can even dive them and then rise them to the surface again which has converted them to some form of Sailing U-Boat Hybrid

PN: Dear dear Devs: Pleeease give me small floating blocks!