Submarine Clinometer from HMS Opportune
Fitted with manufacturer's place engraved Crockatt and marked Patt. 5292. The plate above is marked from 0-10 degrees and an air bubble in the central glass tube visually indicated the list or heel on the boat. Lamps are fitted above and in service there would have been lit up to indicate the degrees of list. The instrument is set in a varnished mahogany base. On the back is scratched HM/SM Oportune which was an Oberon class submarine of 1610 tons which was launched in 1964 and broken up in Portsmouth in 1996. Measures 22.5" (57 cm).