Fisher Space Pen doesn't rely on gravity to make it work, thus enabling it to write underwater or upside down.
Pens + Pencils The New York Public Library Shop
Fisher Bullet Space Pen, Chrome
Pens + Pencils The New York Public Library Shop
Only at NYPL The New York Public Library Shop
Kikkerland Retro Pens, Set of 5, Multi (4308-A) : Rollerball Pens : Office Products
New Books: NYPL Vintage Inspired T-Shirt Large
Fisher Space Pen Classic The New York Public Library Shop
Pens + Pencils The New York Public Library Shop
Treasures to Be Un-Hidden at New York Public Library - The New