The Namiki Vanishing Point (now in the Pilot-branded Mark II) is a fountain pen that, with a push of a long plunger at the back end, retracts into the body and is sealed within a patented (and, more importantly, highly effective) seal. I had one of the original models years ago that I broke by dropping it on its point (I suck); the new version has a different body with somewhat higher production values, though I haven’t decided whether I like the weight of the new model. (A bit heavier, which I normally like in a pen, but it’s not what I was expecting here.)

It also has a very good nib for its price point (14k, pretty flexible).