Herreshoff Manufacturing was located in Bristol, R.I., and built 100 PT- Boats during WWII.
The Herreshoff Manufacturing Co. was a small Rhode Island based boat builder that was awarded a contract to supply the Navy with 100 PT boats during the war. Due to their smaller size, and with the inability to get materials, and employees, the company notified its employees in 1944 that the company would shut down.
With this PT- Boat (pin) made as a tie clasp, I am assuming it was intended to be given out to employees, but very well could have been sent out to crews. The company name is on the pin.
2.5 inches. Marked STERLING.