US Navy Marathon quartz ships chronometer

[River Rat 1]

Saw this the other day on eBay. Was sold for parts was missing batteries so seller had no idea if it worked. Had make offer I offered 75 bucks it's mine now. Should get it next week. The batteries are tough to get LR50 1.5-volt batteries used in cameras and other equipment. Only place I found batteries was online no local stores carry them. So ordered a few batteries might work I can see why the seller did not test it too much trouble getting batteries. These were used by the US Navy for navigation and replaced the Hamilton Model 21 chronometers now these are probably gone from the Navy this is the second type quartz chronometer the Navy used the other was by Waltham I got one of those too. Bet the Navy don't use ether one today. Make me wonder what they use today as back up if an enemy takes out our GPS satellites we would be screwed. Marathon also made wristwatches for the US Military.

[River Rat 1]

Well received it some days ago then had to wait for the batteries to come. Good news the movement works and the hacking. Bad news the stem that screws into the movement the screw tip in the movement snapped off and is in the stem. The movement were the hole and arrow there should be a threaded piece coming out. That changes the time. The work around is you hack it when the correct time matches un-hack it or you can remove the dial four screws and move the hands by hand. Anyone wonder how it was secured they had a lot of Hamilton model 21 this replaced outer boxes that has two holes on the side to secure to the chart table.  I will have my watchmaker look at it to see if he can repair it. It works tells time for a year if I have to do the work around to change the time once a year not bad for 75 bucks for one of the last chronometers the US Navy used. Now I have both the last chronometers the Navy used.

[River Rat 1]

Anyone knows the last year the US Navy used the Hamilton Model 21 and these quartz chronometers replaced them in the US Navy