Which northwest Adelaide suburb, and birthplace of Mark Harrity the fast bowler, shares its name with a system of flag signalling?
Mark Harrity:  He was born in Semaphore, a suburb of Adelaide. Semaphore, South Australia: Semaphore is a suburb in the Australian state of South Australia located in north-west of Adelaide on the Gulf St Vincent coastline of the LeFevre Peninsula about 14 km from the Adelaide city centre.
Semaphore