Within the Navigator series of Tissot, which we mainly know of their chronograph watches, we can also find an interesting series of stopwatches. Produced in 1976 and targeted at the youth to use in a leasure and sporty environment. These stopwatches were powered by the manual wound Tissot 4XXX calibre a.k.a. Lemania 4000 movement. Some had a waterproof white fiberglass casing, others a radiant orange dial. In different time scales Tissot offered the full range in time keeping.

Reference 340.243 and 340.221 (Referee Timer)

I succeeded in acquiring not one but two Tissot Navigator stopwatches. Both in excellent condition. Both in the white fiberglass waterproof case. Both still having the original triangular metal bow. The reference 340.243 has a single pusher at 12 o'clock.  

The refence 340.221 is the Referee stopwatch with several types of sports on the dial. Football (45 minutes), Rugby (40 minutes), Field Hockey (35 minutes), Handball (30 minutes), Ice Hockey and Basketball (20 minutes) and Waterpolo (5 minutes). 

The Tissot Calibre 4xxx series