Circa 1959-1961.
Here is a vintage Hamilton Sea-Mate in a 10K yellow rolled gold plated case with a stainless steel back. The Sea Mate was part of the "Sea" range of watches manufactured by Hamilton in the 1960s and appears to be the only square bodied watch from the series. This charming timepiece sets and winds smoothly thanks to a serviced Hamilton 671 caliber manual wind movement with 17 jewels that kept great time over a 24 hour period. The case measures approximately 30mm wide x 40mm in overall length. The inside back case is marked: Hamilton Watch Co., Lancaster P.A., 10K RGP Bezel, Stainless Steel Back, P009412, Star W.C. Co.
Here is a vintage Hamilton Sea-Mate in a 10K yellow rolled gold plated case with a stainless steel back. The Sea Mate was part of the "Sea" range of watches manufactured by Hamilton in the 1960s and appears to be the only square bodied watch from the series. This charming timepiece sets and winds smoothly thanks to a serviced Hamilton 671 caliber manual wind movement with 17 jewels that kept great time over a 24 hour period. The case measures approximately 30mm wide x 40mm in overall length. The inside back case is marked: Hamilton Watch Co., Lancaster P.A., 10K RGP Bezel, Stainless Steel Back, P009412, Star W.C. Co.