Wrist sundials: have sun-fun

When pupils were attending True Time Workshop (2009-2011), many of the discussed ideas were inspired by "what-can-be-found-in-internet".

This picture was found among others according to search request wrist watch sundials. The task was to think about different implementations of this idea with the respect to usability, safety and commercial potention.
Here is the photo of the model, made for 33mm diameter of the dial. Such dimentions are suitable for unisex size of wrist watch body. The gnomon is just a mark made on the inner surfuce of the glass. The height of gnomon is 6 mm above dial's surface.
Actually, the dial may be marked differently. Here is how hour and declination lines look like together. We can combine markings for different gnomons on one dial and get very complicated view of it.

Other ideas for implementation:

  1. All new mobiles have compass-level application, thus, alignement of such sundials is a very simple task nowdays.
  2. You can have changable dials for different occasions.
  3. A special braslet can be used for latitude adjustment.