Lewis Hamilton admits it is going to be "challenging" on Saturday after heavy rain put the teams on the back foot in Belgium.
Returning to work after the summer break, the Formula One teams and drivers found themselves with little to do at times as the rain came down at Spa.
The heavy rain resulted in standing water and even rivers, making the conditions too treacherous for the drivers to venture out in the afternoon.
They did, however, put in a few laps at the very end with Hamilton putting in two tours of the circuit without setting a lap time. That brought his total number of laps for Friday up to seven.
"It's been incredibly wet today - there were lots of rivers running across the track and lots of aquaplaning, so you had to be very wary out there," said the McLaren driver.
"There's no real benefit to be gained from pushing the car, but there are always things we can learn, so we did a couple of installation laps to check the effects of the upgrades we've brought to this race and see how the tyres switch on in the wet.
"It's going to be challenging tomorrow, but everyone is in the same boat - no joke intended! If it dries out, the track will be green in the morning, so you'll be setting the car up during a couple of runs in FP3."
But despite having to contend with the rain and rivers, Hamilton was happy to be back at work.
"It's great to be back out on track," he said. "A Formula 1 car would be fun to drive even if it were snowing, so I just enjoyed every little bit of lap I had."
His team-mate Jenson Button put in a few more laps, covering eight in the morning and two later in the afternoon, revealing that certain parts of the circuit were worse than others.
"For most of the lap, you're not really pushing - then, halfway down the Kemmel straight, it suddenly gets wetter," he said.
"It's a different type of asphalt, which doesn't drain as well. As soon as you hit that, you feel the car slow down and then it starts to spin its wheels.
"Hopefully, the worst conditions have blown over and we can get down to business tomorrow. It's been such a long break that we just want to get out there and enjoy ourselves."