17-ton surface effect ship XRL (Experimental, Research, "L" for displacement) testcraft being tested at Carderock, Md.
U.S. Department of the Navy
<a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/imgsrv/download/pdf?id=mdp.39015076083875;orient=0;size=100;seq=756;num=3388;attachment=0">Fiscal year 1976 and July-September 1976 transition period authorization for military procurement</a>, Statement of Rear Adm. William L. Read, United States Navy, Director, Ship Acquisition Division, pt. 6, p. 3388