When you travelling in Russia, i think you often listening the warnings about pickpockets.
In Peterhof our guide give the warning about pickpockets at the tricky fountains.
They using situation, when the tourists are looking with fascinated the fountains.
Usually there are lot of people together and you don't detect the time, when you purse was stolen.
Not too dire a warning here, just a note that the scenery on the approach to Peterhof isn't really very spectacular. The wind blows quite hard due to the speed of the Hydrofoil, so it's difficult to really enjoy what you do pass.
If you enjoy boating and waterways, be sure to do a tour of the canals of St. Petersburg. . .they're much prettier and done at a speed that's appropriate for lesiure enjoyment.
It's worth noting that there's a decidedly playful side to the fountains and grounds ~ a few "trick" fountains have been designed to spray people who step too close. . .and placed in different areas of the park. :-)