The anthology Monsarrat At Sea, originally published in 1975, includes Three Corvettes: a trio of short works published independently during WWII, collected into a single volume in 1945, and reprinted multiple times over the next 30 years.

When Cassell Military Paperbacks reprinted Monsarrat At Sea in 2000, they used Three Corvettes as the title for the entire work.  Only the Cassell edition of Three Corvettes (ISBN 0304354449), or other editions known to contain the same set of stories, should be combined into Monsarrat at Sea.