vector altimeter

[jjym]

I just recently got the Vector as a birthday gift and I have a question about the altimeter. I actually went to the ocean to set the altitude and came home. The elevation at home was 50meters. After a while the watch started to fluctuate up and down. It went up about 10meters but down about 55meters so that It was reading below sea level. I know that barometric pressure has a bit to do with this setting but should it change that much? Also, what should I do to get a somewhat accurate altitude bearing because even at sea level the barometric pressure will affect the altitude reading. The manual says to go to a topo map for a reference altitude to set the altitude but wouldn't baro pressure affect the reading there too? Which do I set the sea level pressure or the reference altitude? Doesn't one affect the other directly?
Any help would be greatly appreciated.

P.S. Is there an average static sea level pressure that could be set so that that the actual altitude could be worked out by way of manipulating the absolute barometric pressure and temperature?

	Suunto Vector - Click for more info Suunto's original Wristop Computer, the Vector changed the face of sport watches forever with its groundbreaking combination of features, including an altimeter, barometer, electronic compass, digital log book, and watch. Introduced in 1998, the Vector was the first watch to make it to the summit of Mt. Everest. In addition, the Vector won the prestigious European Outdoor Award - Product of the Year in 1999/2000.

[AltimeterGuy]

Please remember a 1 mbar increase in Sea Level adjusted barometric pressure will decrease your altimeter 10 meters and vice versa. In Imperial terms, a .05 inHG increase in Sea Level adjusted barometric pressure will decrease your altimeter 50 feet and vice versa.

AltimeterGuy