In @Aeroseer777 's defense, I think he/she wasn't seeking a second opinion about what the device was, but rather just a line-by-line translation of all the text.
Here is my attempt at that:
距離計 range finder
探信儀用 for use with passive sonar
單位（粁） Units: kilometers
精 工 舍 Seiko House (what later became Seiko Corporation)
Picture of the thing here. (The guy who posted the picture to the blog isn't quite sure of the nature of the thing himself). I mean, it is unclear how the watch is used as a range-finder. Maybe the OP's watch is intact, and it's intended use is more obvious.
海軍用？距離計 探信儀用 秒時計？ ( その他趣味 ) - アンティークウォッチ を探して 東西南北 - Yahoo!ブログ