The hydros I saw in the 70s were all nitro powered outrigger "Crapshooter" hulls using very high nitro content fuel, 60% in some cases. Highest speed was high 90 something , they didnt make the magic 100mph mark. There is a famous Youtube clip of an electric model on a public park that they claim was worlds fastest. They got one, (I think they said 130mph) run in before being moved-on by the police. Another Youtube clip showed a rocket propelled rigger going VERY fast on UK lake but it destroys itself on a second run. BTW Pierre I was in your area last week for ten days on holiday, GAP.