I'm interested too. Do you have to spend a fortune on a Suunto to get a reliable altitude for OMM 1:40,000?

What about this Silva Ridge one - battery free -

http://www.outdoorgb.com/p/adc_ridge...dBundle=143194

Would that be detailed enough for use in a MM? Already have a Garmin 305(which can give 'instant' GPS based altitude), but of course not allowed in the OMM, because of the GPS...