Jenson Button said he would be concerned about racing in conditions as bad as those the Formula 1 field experienced during Friday's practice sessions for the British Grand Prix.
Both Silverstone practice sessions were rain-affected, and McLaren driver Button said the level of standing water in places was difficult to safely navigate.
"It's tricky out there, it really is," he said. "There's a lot of standing water. When you watch the GP2s you realise just how much standing water there is, there are a lot of people facing the wrong way.
"In the race, you wouldn't want to be racing in those conditions wheel to wheel, because you can't see the aquaplaning until you arrive, so its treacherous conditions."
Williams's Bruno Senna had a heavy accident on the exit of the Becketts section, and Button said this was one of the particularly treacherous areas.
"One of the worst ones is down the Hangar Straight before Stowe, you're doing 290km/h before you cross a river that gives you wheelspin," he said. "When you get wheelspin at that speed in an F1 car, it can snap very easily, and that's the scariest place.
"And probably coming onto the Hangar straight, you had a lot of standing water where Senna crashed, so it's tricky out there and when you're a car on your own, it's not so bad and you can pick your way around, you can lift off where you want, but in race conditions you can't do that.
"So I hope it's not like this on Sunday, hopefully there's not as much standing water."
Button's McLaren team-mate Lewis Hamilton was fastest in the afternoon, and felt the circuit authorities could improve the track's drainage.
"There's lots of aquaplaning here, there's lots of standing water," he said. "It's raining a lot, so it's to be expected. In some areas particularly more so than others, where there doesn't seem to be enough drainage, so that's just an improvement we can make for next year."