NavList:

Geoffrew you said:

Seems to me that a theodolite would have been a better option. Any reason to use a sextant and the attendant paraphernalia in these circumstances?

Geoffrey Kolbe

They certainly had at least one of both, and probably more sextants than theodolites.  Bowers might have been using the theodolite on its tripod that day; they all had their allocated duties to do.  You'll find pictures of the theodolite with all its relevant knobs insulated to prevent cold burns on the www.  In fact, some accounts say that Scott had required Rennick and Bowers to swap duties  from i/c Stores to i/c Hydography, and perhaps surprisingly, Renwick still remained great pals with Bowers.  

Renwick also became great pals with Ponting, which is why he appears in so many of Pontings photographs.  It's always possible that, as it was a nice day, they drew whichever equipment was not alredy in use and went out to record the use of celestial. 

Renwick had a rather sad end.  Remaining in the Royal Navy, he was a Lt Cdr on board HMS Hogue, one of three RN Armoured Cruisers sunk in the space 60 minutes by a single German Submarine E9 in the morning of 22nd September 1914 while on patrol together without their destroyer escort. Hogue was torpedoed while stopped picking up survivors from HMS Aboukir.  It was reported that Rennick who survived the torpedoing gave up his lifejacket to a married man with three children and subsequently drowned. DaveP