Dear Ms. Seigel,
Thank you for posting your request on History Hub!
We searched for "SAGNOTTY" in relation to a cutter but were unable to locate one with that name or with the designation MR. All of the Coast Guard Cutter hull designations begin with W unless it is a small craft, then it begins with CG. It is possible that MR Sagnotty may have been an ensign since the rank is comparable between the Navy and Coast Guard and ensigns are referred to as Mister (MR). Your father may have known Ensign Sagnotty and somehow ended up with his cap.
To determine what vessel(s) your father served on, we suggest that you request a copy of his Merchant Personnel Records. The Merchant Marine Personnel and Licensing Records dated prior to 1968 in the Records of the U.S. Coast Guard (Record Group 26) are in the custody of the National Archives at St. Louis (RL-SL). Please contact RL-SL via email at email@example.com. Include the name, date of birth, dates of service, "Z" number, and date of death, if known, in your request.
Once you have the name of the vessel(s), you may wish to request copies of the muster rolls. We searched the National Archives Catalog and located the Muster Rolls of Coast Guard Ships and Shore Establishments, 1941 - 1949 in the Records of the U.S. Coast Guard (Record Group 26) that include the vessels you seek. For access to and/or copies these records, please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org. The muster rolls will list who served on a vessel for a specific time period.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RL-SL & RDT1. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your family research!
[Some information provided by Nate Patch, Subject Matter Expert]