Originally Posted by Luv2Fly
I thought this might be a bit of over exaggeration, but I checked an air pressure vs altitude chart and you will be a little below half an atmosphere at that altitude. About 7 psi. So your tubes would have been under a lot of extra force on the climb up and if you bled them to compensate at altitude they will be very underinflated by the time you come back down. I didn't think the altitude effect would be that pronounced. Good to know.
Not quite that bad, half an atmosphere is at 6000 metres, the OP's at 6000 feet. Pilots in unpressurised aircraft don't go on oxygen until 10000 feet, if they were down to 7 psi at 6000 they'd be blacking out all over the shop. 7 psi is more like 20000 feet which is IIRC three quarters of the way up Everest ( now that'd be a cool - probably literally - place to go ribbing! Except your engine would'nt go...)
Per the chart below 6000 feet is 0.8 atmospheres or 3 psi down from sea level. Still means I guess if the tube was inflated to 2 psi at sea level it'd be something like ( not sure if the maths is as simple as this) 5 psi over at 6000 feet. Still worth thinking about if you ever found yourself towing over an alpine pass or something, never mind actually boating on a high altitude lake!
Air Pressure and Altitude above Sea Level