Quick question: is there any special procedure for sailling in a thunderstorm?

Depends entirely on the wind. Some have none, most have some, and many have squally winds that may overpower you if you don't shorten sail.

The wisest course is to reef early, and make sure you have enough searoom to leeward of the anticipated wind direction. Don't count on being able to make any distance to windward during the worst of it. Just reach, or close reach, and luff as needed. Put on lifejackets too (and a safety harness if you have one). Pay attention to your compass, as wind direction may change a lot during a squall, and you won't be able to see squat during the heavy rain. If the wind's just too much, I'd say drop all sail, anchor (assuming now you're not too deep to anchor), and wait it out. Usually in 20 minutes the weather's good again (not always, though).

The other concern is lightning. you can't do anything about it, but stay away from the mast and stays, they're electricity conductors. If you have a cabin, your crew is safest down there.

I can't be much more specific, as I don't know whether you're sailing a cruiser or an open boat, and not all t'storms are the same either.

Having been caught out in a nasty RED/PURPLE cell from hell recently in a boat with no reefs I can give ya a tip that worked for me. After getting knocked down once and being pushed sideways before I could get her around, I left the jib set for a Starboard tack (backwinded) and set her on a Port tack about 15 degrees off the wind with the boom all the way to windward. This allowed me to sail at about three knots dead into a 40+ knot gale until I could reach a Windward shore and escape the wind, all while being POUNDED by 3/4" hail and having lightning like I haven't seen since Texas, scare the crap outta me. This little adwenture tought me much about what my boat and myself could handle. It also taught me that just because ya haven't seen storms like that in 11 yrs. of living someplace, doesn't mean they cannot happen.

Ummm.. CharlieCobra, I believe that's normally called heaving to.

Yeah, 'cept you don't normally end-up moving forward at 3 kts when you're hove to, IIUC .

Jim

Tell ya what a friend of mine did one time when we got caught in the middle of the lake by one of the "low odds" thunderstorms that were predicted: Down went the sails and on went the iron genny.

And I gotta tell ya: Being out in the middle of an area as flat as a billiards table with a 40' lightning rod sticking up in the air, with lightning crashing down all around you, is most definitely not amusing.

My friend: Don't worry, the mast on this boat is stepped thought to the hull. It's well-grounded.
Me: Here we are, sitting in the cockpit of a thoroughly soaking wet boat, ourselves soaking wet, that mast not 10' away, and you think that's going to help, eh?

Jim

Saurav...drop your sails and turn the motor on & head into the wind.It'll all be over in 20 minutes.

yeah motoring sounds like a plan but what about lighting?

It depends on the boat design. Some designs don't heave-to well, and will forereach at about that speed.

saurav...
1. Disconnect any electronics you can.
2. Stay away from metal/shrouds etc....down below is best.
3. Find a boat with a taller mast and get near it!! (LOL)