140 foot icebreaking tug with new davit
The In-service Vessel Sustainment Program modifications for the 140 foot domestic icebreaking tugs include a new davit that should make boat launching much quicker and easier. Compare the photo above with the earlier photo below. You can see that the O-1 deck has been extended out to the side of the hull and the new davit replaced a kingpost style derrick. Here is the vendor’s press release that provided the more recent photo. 
Katmai Bay (WTGB 101) is tied to the pier at Group Sault Saint Marie, Michigan, Sept. 2001. USCG photo by PA1 Harry C. Craft III
Thanks to Lee for bringing this to my attention.
Chuck Hill's CG Blog 
The eight 140 ft icebreaking tug has completed the service life extension modifications. Only one more to go. https://www.dcms.uscg.mil/Our-Organization/Assistant-Commandant-for-Acquisitions-CG-9/Newsroom/Latest-Acquisition-News/Article/1984299/renovation-completed-on-eighth-140-foot-icebreaking-tug/
“Coast Guard Cutter Mobile Bay departed from the Coast Guard Yard in Curtis Bay, Maryland, Oct. 1, following completion of its service life extension project as part of the In-Service Vessel Sustainment (ISVS) Program. Mobile Bay is the eighth of nine 140-foot icebreaking tugs to undergo service life extension work through ISVS. The work will extend each cutter’s service life by 15 years and includes upgrades to propulsion and electrical systems, replacement of the boat-launching davit and habitability improvements. The tugs entered service in the 1970s. Mobile Bay will return to Sturgeon Bay, Wisconsin.
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The Acquisitions Directorate, (CG-9) reports,
“The In-Service Vessel Sustainment (ISVS) Program in partnership with Coast Guard Yard personnel completed scheduled work on Coast Guard Cutter Neah Bay Sept. 22, 2023, successfully marking the conclusion of on-site and mobile road show projects to install heating, ventilation and air conditioning (HVAC) equipment onboard nine 140-foot Bay-class icebreaking tugs that operate throughout Coast Guard Districts 1 and 9.
“Over three years, a 12-person project team oversaw a comprehensive plan to update each cutter’s boilers, piping and air handling units and execute related work to aid front-line Coast Guard crews operating in extreme cold weather environments. Efficiencies developed during work on the nine tugs eventually reduced the HVAC project duration from 44 to 24 days.
“The ISVS Program restores mission readiness, improves reliability and reduces maintenance costs of the service’s legacy cutter fleet.
“For more information: In-Service Vessel Sustainment Program page.