Rockaway Belle is listed as Army tug-transport T-1, built by Simms Brothers, Dorchester MA, 1942. 'T-boats' were 65-foot, 45 ton diesel-powered, passenger-cargo boats that doubled as harbor tugs. 170 of them were constructed during WWII, and many more afterwards. From 1940 through 1951 all T-Boats were built of wood, thereafter steel. Rockaway Belle was T-1 of the T-1 class, sold as surplus in 1947.
Note: In 2020 Round Valley began a period of maintenance which is expected to last several years. During this time, the water volume is reduced by a third. My completely offhand guess is that this will reduce the water level by around ten feet. In the shallow areas where diving is practical, this will significantly alter the shoreline.
The "Sachem" wreck is typical of the remains of many unknown wooden sailing ships that are found off the coast. Three parallel sets of ribs and scattered decking between provide good habitat for lobster. The wreck sits in 60' of water on a clean sandy bottom and visibility is usually good on this site. Fairly large and scattered, it also provides a good opportunity for the spearfisherman.