There are many styles in the Nautilus series but the dials are always round and they always had the 505 movement. Some were stainless steel (500), others in 10K Gold Filled (400), some in 14K solid gold (200) and others in 10K Rolled Gold Plate (600).

Sadly, many of the Nautilus stainless steel examples have been sacrificed over the years to become donor watches for the more collectible asymmetric and solid gold cased electrics.

The first seven photographs below is of the Nautilus 403. As you can see, this is a pocket watch but contains the normal 505 movement and was released in 1965. However, it sold very poorly; those people in 1965 who still wanted a pocket watch, rather than wristwatch, were not the sort of people who wanted a new fangled electric watch. As a result, the 403 is very scarce and one of the hardest Hamilton Electrics to find. My 403 started as a case only; I added a 505 movement and was kindly given a spare dial from a Nautilus 602 which is similar to the dial from a 403.

Hamilton Nautilus 403	Hamilton Nautilus 403	Hamilton Nautilus 403	Hamilton Nautilus 403	Hamilton Nautilus 403	Hamilton Nautilus 403 & even rarer electric Vantage pocket watch
Hamilton Nautilus 403	Hamilton Nautilus 404	Hamilton Nautilus 405	Hamilton Nautilus 405	Hamilton Nautilus 405	Hamilton Nautilus 450

500 Series : Round Cased models in Stainless Steel Cases

Hamilton Nautilus 500

Hamilton 'Thirteen' Presentation watch based on a Nautilus 502

Hamilton 'Thirteen' Presentation watch based on a Nautilus 502

600 Series : Round Cased models in 10K Rolled Gold Plate

Hamilton Nautilus 600	Hamilton Nautilus 601	Hamilton Nautilus 601	Hamilton Nautilus 601	Hamilton Nautilus 602	Hamilton Nautilus 602 (three of them!)
Hamilton Nautilus 602	Hamilton Nautilus 604	Hamilton Nautilus 604