Artifacts of WWI subchaser service are scattered around, and require some hunting to locate. There are several sets of relevant collections held by museums, libraries and archives that are worthy of note for their value and relevance to the study of WWI submarine chasers. Some are listed here.
The Coolspring Power Museum, in Coolspring, PA, has in its collection a working example of the Standard Auxiliary engine, the type of engine used on subchasers in WWI to power the batteries for the boat and to supply compressed air for starting the main engines.
The Naval Historical Center has an excellent online photo archive of WWI vessels, including a number of fine shots of chasers. Follow the links: Photographic Section >> Online Library of Selected Images >> U.S. Navy Ships Listed Alphabetically by Name and click on "S" for subchaser (and scroll down to the "SC" entries). Even more exciting is a set of pages for early documents of the Office of Naval Intelligence. These are worth looking at. Go to the Reading Room page, to the section on the WWI time frame. ONI Publication No. 14, Antisubmarine Information, has quite a lot of content on submarine chaser activities.
The National World War I Museum in Kansas City is dedicated to the men and women who served in WWI. The archives includes a collection of submarine chaser photos donated by the daughter of Boatswain's mate, 2nd class, Stephen W. Ostrander: From the service of Boatswain's mate, 2nd class, Stephen W. Ostrander, U.S. Navy. Accession number 2003.9. Several photos from the museum are posted in The Subchaser Archives.
The New England Wireless and Steam Museum, in East Greenwich, RI, holds many artifacts of early radio communications. Among its holdings is a radio telephone set of the type used in the WWI subchasers, the CW 926, designed by Raymond Heising of Western Electric.