In the early 1950s, Sheaffer faced significant challenges on at least two fronts. First, there was the tremendous popularity of the Parker 51, with its sleek, modern design. Second, the ballpoint pen was making inroads, boasting ease of use with no messy dipping or filling.
Sheaffer responded with the Snorkel. Its look was clearly influenced by the 51, but with some uniquely Sheaffer elements. Best of all, it could be filled without any mess thanks to a tube that extended from the feed to suck up ink. This meant that the nib need not be submerged to fill the pen.
Most modern fountain pen users are unlikely to be put off by the alleged messiness of filling a pen, but the Snorkel's eponymous tube is unbeatable for getting those last precious drops out of an ink bottle.
Buying a Snorkel
The Snorkel is such a uniformly great pen that your choices in selecting one will be largely aesthetic. Personally, I'm a fan of the tubular "Triumph"-style nib, but Snorkels are also available with conventional nibs.
The original color range was fairly subdued, but starting in the mid-1950s the palette expanded to include colors of Fiestaware-like vibrancy. There were all-metal models (these were rarer), and very attractive "Crest" and "Clipper" models with plastic bodies and metal caps. (See David Isaacson's article for explanations of the 13(!) model names used for the Snorkel.)
For a functional, but "nothing special," Snorkel, you can expect to pay roughly $70-150 US.
For a pen that boasts the most complex filling system in the history of fountain pens, the Snorkel is surprisingly easy to fill.
Unscrew the blind cap and pull back. This will expose the metal "Touchdown" tube that surrounds the ink sac, and will also cause the snorkel tube to extend. Put the end of the snorkel tube in the ink and push the blind cap back into position. As you tighten the blind cap, the snorkel tube will retract into the feed. You're ready to write.
In principle, cleaning a Snorkel isn't much different from any other sac-filling pen. Just draw water up into the sac and expel it. Repeat until the water comes out clean. In practice, this is easier than cleaning a lever-filling pen, since the Snorkel's filling mechanism can be operated more quickly.
The Snorkel is a solid pen that will not disappoint. As with all vintage Sheaffers, the nibs are excellent, though generally very firm. The relatively low cost on the secondary market and the large number of models and colors makes the pen a nice option for a collection as well as a great user.
If you like the idea of the snorkel tube, but don't like the slim body of the Snorkel, you might look at the Sheaffer PFM, a later model that uses the same filling mechanism, but has a chunkier build and a beautiful inlaid nib.
Brian Gray's explanation of his pneumatic filling mechanism discusses how a similar filling mechanism works and includes a helpful video.
David Isaacson's Sheaffer Snorkel Collector's Guide helps to decipher the profusion of model names for the Snorkel.
Richard Binder's extensive profile page on the Snorkel is helpful for determining the age of your Snorkel and lists many of the colors.
Richard Binder's Anatomy of a Fountain Pen III: Sheaffer's Snorkel explains the complex internal workings of the filling mechanism, with detailed diagrams.