Welcome to the first practice session for the German Grand Prix at Hockenheim.

It's very wet here at the circuit, it has been raining all morning so running could be fairly limited this morning.

Hamilton is still in his rain coat and showing no signs of getting in his car. However, Schumacher is getting ready and will get a very warm reception from his home crowd when he splashes around for an installation lap in the next ten minutes or so.

The rain is bad news for McLaren who were hoping to run their blown diffuser this morning and get some useful data on it.

The first cars are out on track, just getting a feeling for the grip. Glock is twitching around in the Virgin through the Stadium section, it really is very wet out there.

The drivers are out on their wet tyres as opposed to intermediates, however, we are expecting the rain to ease off as the session continues. So if enough cars get out and dry the track we might see some inters out later on - dry tyres are unlikely.

Hulkenberg runs a little wide in his Williams as he starts a second lap. He is having to short shift and make constant inputs on the steering wheel to keep the car in a straight line.

Rosberg, Massa and Schumacher are out on track for their installation laps. Rosberg is starting a second lap out of the pits but is a long way off going full throttle down the back straight.

Schumacher is back in the pitsas Webber and Vettel are out on track. Hamilton and Button have yet to leave the McLaren garage.

The track falls silent and I fear it might stay that way for some time. There isn't a huge amount of information to be gathered in wet conditions although we can hope some of the less experienced drivers head out on track to get some practice in.

Button is now out on track but it will only be a quick installation run.

Kobayashi told that if he wants to go out on the full wet tyres he needs to do it now as they can't risk damaging a set. They only have three sets of full wets and four sets of inters for the whole weekend.

Di Grassi and Alguersuari are providing the entertainment at the moment. Hamilton is getting ready for his first installation lap.

A weather update from Lotus: "Still light rain but easing off, still forecast to stop at 10:25"

Vettel is out on the track pushing quite hard. He did a 1:36.905 but backed off in the final sector and is now on another attempt.

Vettel sets another quick lap with a 1:34.796.

Webber now joins his Red Bull team-mate on track and is about 0.273 off Vettel's time.

Webber sets his fastest time with a 1:34.219 as Vettel runs wide at turn eight. Webber then locks up and runs wide at the hairpin. So the Red Bull drivers are pushing hard but the conditions are terrible.

Alguersuari is now the fastest driver with a 1:33.402.

Neville asks: "What are the realistic chances of a wet Grand Prix? Surely if that was a possibilty the drivers would find it purposeful to practice under these conditions."

The forecast seems to be changing every hour at the moment but the last one I heard said there was going to be rain on Sunday. That would explain the running at the moment.

Massa is now fastest with a 1:31.981 but is beaten immediately by Webber on a 1:31.019.

Fauzy loses control out of turn three and goes onto the grass. He just managed to hold it all together to the relief of Kovalainen whose car he is driving this morning.

Liuzzi just puts a wheel on the slippery kerb entering the final corner and slides wide.

Rosberg goes fastest with a 1:30.864, a dryish line is starting to appear but it is still very wet out there, especially off line.

Senna runs wide at turn eight, that corner looks wetter than most at the moment. Alguersuari says over the radio that the track is improving and the times are changing but he still wants more practice time.

Liuzzi runs wide again as Button heads out on track. We still haven't seen Hamilton out on track again.

Massa has a huge 360 degree spin coming out of turn three. He stamped on the throttle coming onto the straight and the car stepped out on him very violently. No damage to the car but a little reminder of how tricky the conditions are at the moment.

Kubica is off the track in the gravel in the stadium section, he just ran wide into the banked turn 13. And Massa has a copycat accident at the same point. No damage to the cars.

Barrichello spins exiting turn three and slides down the track sideways. So a lot of the drivers are pushing hard at the moment and making mistakes.

Silviu asks: "Why do you think the McLarens are still in the pits? Wouldn't it help to test the new diffuser on wet?"

McLaren don't think they will learn that much in the wet as the track is either drying or getting wetter constantly and it becomes very difficult to make comparisons. But Button is out now and Hamilton did a quick run a minute ago.

Button says over the radio that the rear grip is terrible at the moment, but that could be because his rear tyres are wearing quite a lot as the track dries. That is why it is so difficult for McLaren to know what is going on at the back of the car.

Rosberg sets a new fastest lap with a 1:29.419. The track is much drier now and they might soon go out on intermediates.

Renault mechanics are having a very close look at the right rear brake of Kubica's car.

Kobayashi is the first out on intermediate tyres and has a very violent spin in the Sauber at turn six. No damage done though.

Markus asks: "Hi does schumi have a problem? He hasn't been out as much as Rosberg or do you think he´s just saving tyres? He hasn´t had any luck this season except from two races, do you think that his luck will change soon?"

Like you say, I wouldn't read anuthing into the times or the amount of laps the drivers are doing at the moment. It's very impressive watching Rosberg at the moment but as the track changes his set-up will become pretty useless.

As for Schumacher in general. The car is definitely improving at the moment and I would expect him to get some slightly better results over the next few races. But I'm not sure he will beat Rosberg that often. Maybe next year, once he has had some input over the winter on the 2011 car.

Intermediate times are now being set. Hulkenberg sets a 1:29.206 and Webber has set a new fastest time with a 1:29.048.

A dry line is starting to emerge at certain parts of the circuit and at the moment intermediate tyres are the only ones worth using.

Vettel fastest on a very quick lap. He was using the kerbs and even got on the astroturf but held it all together to set a 1:28.735.

Sutil is now the fastest with a 1:28.411. He's always very wuick in the wet and also knows this circuit very well.

A good point by Neville: "Jenson Button seems to be uncomfortable with rear grip most of the time however he always seems to recover and comes on very strong in all the races."

Dave also makes a good point on Schumacher: "I think people need to realize with Schumacher at every team he has been with it was a year of getting the car and team built up to the way he wants it. Give it time and I bet he will be winning again. He wants it too bad…."

Desmond asks: "Any information on what's going to happen with McLaren if they don't get the new diffuser to work properly? Will they abandon it for the second time or will they run it anyway and take the risk to end up in the midfield in qualifying on Saturday?"

They will not run it if they are not happy with it or don't get enough dry running. But they have also said they are willing to run it on one car and not the other. Hamilton wanted to keep it at Silverstone so it will be intresting to see what happens there.

Massa runs wide into turn 12. He just didn't get the nose of the car in properly.

Hamilton has a huge accident and the car is in pieces. Three corners of damage on that McLaren, he is very unhappy but unscathed.

He clipped the kerb on the apex of turn three, the car switched ends on him, got on the grass and he had no grip to stop himself hitting the barrier. There is a lot of rear end damage and both left wheels are hanging off.

So, just 20 mninutes remaining and the track is looking wuite dry at the moment. Brave drivers might try slick tyres but it will be a bit risky.

Massa is off the track again at the final corner. He always struggles to get temperature in the tyres and that seems to have been a problem for him today.

Schumacher has still only completed 10 laps and is currently a long way down the order having not set a time on inters. We'll keep an eye on the Mercedes garage to see if we can get any more info.

McLaren confirm that they do have a spare blown diffuser floor, so Hamilton's car can be repaired as it was.

Senna spins off in the final corner and beaches his car in the gravel. He just got off the dry line and that was enough to spin him around.

Despite his problems, Massa is now third fastest and 0.275 off Sutil's pace. Buemi is second fastest, 0.268 off Sutil.

Rosberg sets the fastest time with a 1:27.448. Three German drivers in the top five now - local knowledge in the wet is obviously helping.

Massa is now fastest of all with a 1:26.850, the track is improving dramatically at the moment.

Webber has dry tyres on his car in the garage but is debating whether to head out on track.

Vettel is heading out on inters. Petrov sets the second fastest lap on inters.

Sutil is now fastest with a 1:26.314 as the track dries.

Vettel is about to set the fastest lap bar any mistakes in the final sector ... but hits traffic behind Trulli and loses a lot of time and returns to the pits.

Alguersuari on the slick tyres and spins. Schumacher is now back out on the track on full wets. An odd decision and his time won't lift him from the 23rd in the standings.

And Schumacher pits at the end of that lap.

As the chequered flag comes out Sutil is still over a second faster than anyone else.

So, Sutil holds onto the top spot a full second ahead of Massa and Button. But those times don't tell us a huge amount about the pecking order.

The big news is that Hamilton crashed out. His car is now back in the pits and being rebuilt. He should be back out for session two but his team will have to work very hard over the next two hours. Join us for FP2 this afternoon and what should be another wet and exciting session.