Luc,
Other advantages of the VSP were discovered during the 30s and 40s:
The sea keeping ability was first demonstrated when
Helgoland was drafted into seagoing service. The VSP was discovered to be less likely to break free in a swell. The propeller wash adhered to the stern and damped the pitching somewhat.
A 27m, 220 Hp, 200-passenger ship operated by Société des Auto-Bateaux de Nantes on the Loire, with many stops, was able to reduce the normal trip time from one hour 15 minutes to 45 minutes because off her superior docking ability. She was able to stop in her own length from 12.7 knots.
There were similar experiences on the Rhine, beginning in 1936.
The ferryboat Durme, on the River Schelde was the first Belgian ship to use the VSP. (1936)
Six new motorboats were fitted with VSPs for use on canals in Venice because the wash is upwards and does not extend low enough to undermine foundations.
After the war, the US Navy wanted to get an undamaged German minesweeper, and found the 20-knot
R148 in IJmuiden. After an unsuccessful attempt to get a transport vessel, they decided to send her across the Atlantic under her own power with a German naval crew under Oberleutnant Richard.
Lieutenant M.J. Talbot and three GIs went along as guards. Don’t ask me what they expected to do in the middle of the ocean if the crew turned out to be sore losers.
After fitting out with 12 tons of fuel in barrels, she left Le Havre on October 17, 1945. Past the Azores, she ran into a hurricane with 7.6 meter waves. The bow rose 11 meters out of the water on the crest of a wave. She began to roll by as much as 47 degrees. In his log, the captain wrote: “A minesweeper with screws would not have survived this swell because waves 20 degrees on the port bow would have capsized itâ€.