The War Diaries for the HM HS Vita are only available from June 1917 onward. Below is the best I can do to trace the Vita’s movements from commissioning to when the War Diary starts:
SS VITA – Troop Transport:
14 April, 1915 Bushire. 8.35am: Stopped by SS VITA, drew stores
3 Aug, 1915 Basrah. 5.15am: SS VITA down river
21 Dec, 1915 Marseilles. Troops Boarded the SS Vita at Marseilles
21 Jan, 1916 Basrah. Troops Disembarked SS Vita at Basrah
29 Jan, 1916 Basra. Arrangements were made to dispatch a Medical Officer with practical knowledge of Plague and an Assistant Surgeon skilled in Bacteriology on HT VITA proceeding to Bar to take troops off NILE.
2 Mar, 1916 Basrah. 10.10am: VITA down river
3 Mar, 1916 Basra. Specialist MO with Assistant Surgeon BROWN left on HT VITA for transport NILE at KUWAIT to mitigate Plague outbreak on that ship.
4 Mar, 1916 Troops on NILE being transhipped to HT VITA for Basra.
7 Mar, 1916 It was decided to Quarantine and disinfect troops on the VITA and NILE. A batch of 500.
Note: The War Diary for Divisional Troops: 56 Brigade Royal Field Artillery (WO 95/5151/4) also shows HMT VITA at Shatt el-Arab on 4 Mar, 1916.
HMHS VITA – Hospital Ship:
21, May, 1916 Basra. The VITA arrived on her first trip [as a Hospital Ship].
23 May, 1916 Basra. Dispatched the VITA with 17 Officers and 341 other ranks and the “Chackdara” with 12 B officers and 260 other ranks.
29 May, 1916 Bombay. 6.30am: Hospital ship VITA arrived
6 June, 1916 Bombay. 1.00pm: Hospital ship VITA proceeded
11 June, 1916 Basra. [No 33 BGH personnel arrived on VITA. 33 Officers & 187 men].
1 July, 1916 Busrah. Hospital Ship VITA.
3 July, 1916 Busrah. Hospital Ship VITA departed to India. 16 British Officers, British Other Ranks 205, Indian Officers 14, Indian Other Ranks 157.
16 July, 1916 BASRA. Hospital Ship VITA arrived 6:15pm.
17 Jul, 1916 BASRA. Sick & Wounded for transfer to HS DONGOLA. British Officers 25; British Other Ranks 500.
18 Jul, 1916 BASRA. VITA departed to Bar.
19 Jul, 1916 BASRA. VITA arrived from Bar.
20 Jul, 1916 BASRA. Hospital Ship VITA departed 12:20pm. Sick & Wounded to India.
20 July, 1916 Mohammerah. 10.20am: 69 ratings discharged sick to SS VITA
2 Aug, 1916 BASRA. Hospital Ship VITA arrived.
4 Aug, 1916 Basrah. HMHS Vita left @ 8:15am
4 Aug, 1916 BASRA. VITA departed 8:30am. Sick & Wounded to HT MADRAS. BO 21, BOR 216, IOR 248.
5 Aug, 1916 BASRA. Hospital Ship VITA arrived 5:15pm.
7 Aug, 1916 BASRA. Hospital Ship VITA departed 7:00am. Sick & Wounded to India. BO 5, BOR 389.
7 Aug, 1916 Abadan. 9.50am: Two invalids discharged to HMHS Vita
19 Aug, 1916 At Sea. 9.10pm: HMHS VITA passed, west
21 Aug, 1916 BASRA. Hospital Ship VITA arrived 12:15pm.
22 Aug, 1916 BASRA. VITA departed. Sick to Bar 7:15am.
23 Aug, 1916 BASRA. VITA transfer sick to HS DEVANA. BO 17; BOR 378.
24 Aug, 1916 BASRA. VITA departed. Sick & Wounded to Bar. 7:30am.
25 Aug, 1916 BASRA. VITA Sick & Wounded for Transfer to HS MADRAS. IOR 499.
26 Aug, 1916 BASRA. Hospital Ship VITA arrived from Bar. 2:15pm.
28 Aug, 1916 BASRA. Hospital Ship VITA sick to Bar. 6:00am. Sick for transfer to HS DONGOLA. BO 21; BOR 407.
29 Aug, 1916 BASRA. Hospital Ship VITA arrived 6:00pm
30 Aug, 1916 BASRA. VITA departed to India. 6:00am. IO 3; IOR 374.
12 Sep, 1916 BASRA. Hospital Ship VITA arrived 1:00pm.
13 Sep, 1916 BUSRA. Hospital Ship VITA departed 6:00am. Sick to India BO 10; IO 4; IOR 224. Follrs 150.
27 Sep, 1916 BUSRA. Hospital Ship VITA arrived 5:30pm.
28 Sep, 1916 Basra. Told that VITA, from Bombay, was bringing repatriated PoWs.
30 Sep, 1916 BUSRA. Hospital Ship VITA departed 6:00am. British sick to Bar, Indian sick to Bombay.
18 Oct, 1916 Basrah. 6:20am: VITA passed down
12 Nov, 1916 Basrah. 1:15pm: Hospital Ship VITA passed down
9 Dec, 1916 Zanzibar. 1.00pm: HMHS Vita arrived.
11 Dec, 1916 Dar-es-Salaam. 4:30pm: HMHS Vita arrived.
17 Dec, 1916 Zanzibar. 6.00am: H.S. Vita sailed.
15 Feb, 1917 Basrah. Men discharged to HS Vita
13 Mar, 1917 At Sea. 8.40am: Closed HS Vita
12 Apr, 1917 At Sea. 7.40pm: HS Vita passed, Bombay to Basra.
Source: http://www.firstworldwar.com/diaries/edwinjones.htm
Source: https://www.naval-history.net
Source: WO 95/5238/3. Headquarters Branches and Services: Assistant Director Medical Services.
Source: WO 95/5241/3. Headquarters Branches and Services: Embarkation Commandant.