an Entity references as follows:
The Hydrofoil Mystery was written in 1999 by Canadian author Eric Walters. It is about a teenage boy named Billy McCracken, whose mother arranges for him to go away for the summer to work with none other than the well-known inventor of the telephone, Alexander Graham Bell. Billy expects his summer to be boring, but with the German U-boats endangering the maritime coast, his work with Bell's hydrofoil becomes an adventure.