Ron van Maanen
The call sign consisted of 4 four signal letters making it possible to distinguish them for from other ships in the Commercial Code of signals used all over the world.
GVSB=Ajdaha, steam vessel, 5 guns
GVSC=Assaye, steam vessel, 10 guns
GVSD=Auckland
GVSF=Not used?
GVSH=Beacon, survey vessel
GVSJ=Berenice, steam vessel, 1 gun
GVSK=Not used?
GVSL=Clive, sloop, 14 guns
GVSM=Constance , schooner. 3 guns
GVSN=Coromandel, screw steam vessel, 5 guns
GVSP=Dalhousie, screw steam vessel,
GVSQ=Diana, steam vessel, 2 guns,
GVSR=Elphinstone, sloop, 12 guns,
GVST=Enterprise, steam vessel, 7 guns
GVSW=Euphrates, brig, 8 guns
GVTB=Not used
GVTC=Falkland, sloop, 12 guns
GVTD=Feerooz, steam vessel, 8 guns
GVTF=Fire Queen, steam vessel, 8 guns
GVTH=Not used?
GVTJ=Not used?
GVTK=Hugh Lindsay, steam vessel
GVTL=Not used?
GVTL=Krishna , surveying vessel
GVTN=Lady Canning, steam sloop
GVTP=Mahi, schooner. 3 guns
GVTQ=Not used?
GVTR=Unnamed?, 2 guns
GVTS=Pluto, steam vessel, 6 guns
GVTW=Unnamed?, 7 guns
GVWB=Punjaub,
GVWC=Prince Arthur,
GVWD=Queen,
GVWF=Not used?
GVWH=Semiramis, steam vessel, 8 guns
GVWJ=Sesostria, steam vessel, 6 guns
GVWK=Not used?
GVWL=Spy, surveying vessel
GVWM=Not used?
GVWN=Tenasserim, steam vessel, 11 guns
GVWP=Tigria, brig, 5 guns
GVWQ=Tubal Cain, transport
GVWR=Not used?
GVWS=Victoria, steam vessel, 4 guns
GVWT=Zenobia, steam vessel, 8 guns
Source
J.H. Brown. Mercantile Navy List and annual appendage to the commercial code of signals for all nations. 
