A well intentioned military geek type friend of mine who knows that I like to take notes got me a UZI   (You need to Login or Register. 

Not that I'm the military type and would be using my tactical pen to defend myself against bears or canoeists on a portage.  But the pen is waterproof with gasket seal and has Parker Fisher Space pen ink cartridges that are pressurized to 35 psi.  They claim that "the cartridge that allows ink to flow instantly and dependably no matter what. Whether you need to write under water or upside down, on greasy or dirty surfaces, or in boiling or freezing temperatures, Fisher Space Pen refills have you covered with their waterproof ink. Temperatures of operation range from -30 F (-35 C) to 250 F (121 C)."

Anyway, it was really nice that my friend got me this for the trip and it works really nicely for taken notes even on our freezing October trips.

starwatcher