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.