This Yacht clock was made up by Capt G M Watts Ltd of London, the clock used is a large WW1 period ex British Military Waltham Chrono,  it's a 8 day and has an adjusted movement.

The clock face is about 3 inches across.

I have owned the clock for a long time and every couple of years I have wound it and it has always wound down with no problems. 

I have goggled the serial number and the clock is a 1910 model chrono made in about 1918 /19. it was most likely made by the Waltham watch company for the British during WW1