H.M. Armed Yacht "Aries" was one of the Yacht Patrol vessels based at Dover.  She was lost with all hands on the 31st October 1915.

There appears to be some confusion.   

The Union-Castle at WAR 1914-18 states:-

Calder, H.   Lieut. Comdr. R.N.R. H.M.T. "Grantully Castle"  Killed at Dardanelles