This watch is one of my favorites. They are becoming exceedingly rare. The Eterna Matic KonTiki Super is a massive watch, measuring 41mm wide/ 45mm lug to lug/ 14mm thick. The watch is rated to 200m and has a screw-down crown and a uni-directional bezel. It harbors the ETA cal. 2824 automatic, hacking movement.  The watches pictured above were both issued to Shayetet 13 (S-13, Flotilla 13), the Israeli Defense Forces naval commando unit, probably during the 1970's. The S-13 watches can be identified by 2 sets of ordinance numbers on the case back, which include serial and catalog numbers. There is strong evidence that some of these markings are now being faked and added to civilian watches to create a false provenance. Buyer beware as this could significantly impact the value of the watch.