David,
Some volunteer detachments were presented with transitional wristwatches on their departure. For instance, on 22 Feb 1900, Captains Hanbury and Mason gave "small silver keyless watches in wristlets" to the 14 members of the Maidenhead contingent of the Volunteer Service Company, Royal Berkshire Regiment. Volunteers and yeomen departing from Lincoln were similarly treated (watches presented by Mrs Seely, wife of the local MP).
I expect you will be particularly interested to hear that twelve members of the Pembrokeshire I.Y. received transitional watches from the inhabitants of Haverfordwest, Lady Phillips (of Picton Castle) making the presentation in March 1900. Four Haverford volunteers received similar watches on their return, on 24 May 1901.
It appears that few of these timepieces survived the harsh conditions of life on the veldt. Below is the only extant example I have come across - one of eight 34mm gun-metal watches presented by comrades of "C" & "D" (Devizes) Companies, 2nd V.B. Wiltshire Regt, on 15 Feb 1900. Engraved: "6611 / PVTE W. RUSS / from his / DEVIZES / COMRADES 1900". As you can see, it has seen better days.
The Nottingham Evening Post reported that 820 Trooper William F. Elderkin lost his Lincoln watch on the veldt, but, miraculously, it was found and returned to him in England.
This photograph of a blockhouse garrison of 3rd Bn. Highland Light Infantry shows an officer wearing a full-sized pocket watch on his wrist. This is something I haven't come across before, and conjures up images of WWII bomber crews, with their over-sized 55 mm pilots' watches.
.Courtesy of the McGregor Museum, Kimberley
.Courtesy of the McGregor Museum, Kimberley
..