[Note: This is an unfiltered list of sites that appear to be on-topic.No attempt has been made to confirm the information on these sites.]
The Subchasers of WWI, Theodore Treadwell.
This is a page of a larger site, Splinter Fleet: The Wooden Subchasers of World War II, a site with lots of good information about chasers. It offers a clear and quick introduction to the chasers in WWI, although the site as a whole (as the name suggests) focuses on the subchasers in WWII. Treadwell is author of the book, Splinter Fleet - The Wooden Subchasers of World War II.
A short overview of chasers in WWI and WWII, offering general information about the construction history, armament, and hull numbering system of chasers.
Submarine Chaser Photo Archive, NavSource Naval History Site (Joseph M. Radigan)
WWI and WWII suchaser photo list of various chasers. There are some nice shots.
[Note: see also the Hull Number Photos page of the Chasers section of this site.]
Includes notes on several subchaser incidents.
[Subchaser.org Editor's Note: Mr. Franklyn K. Brown noted that the deck logs of the S.C. #95 indicate that the mine incident ocurred in August of 1919, not September 25, 1919 as this site suggests.]
History of Communications-Electronics in the United States Navy, Captain Linwood S. Howeth, USN (Retired), 1963, pages 297-312. Describes the early history of listening devices, including the listening devices developed during WWI.
Jeffrey Charles' site on the British ML boats, smaller precursors to the 110' U.S. chasers. These boats were built in the U.S. by Elco, the same ship builder that built SC 93, Lt. Dole's first command. Lots of good information and photos.