
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2015 Oct 24, 10:50 +0000
From: David Pike <NoReply_DavidPike@navlist.net>
To: garylapook@pacbell.net
Sent: Friday, October 23, 2015 5:12 PM
Subject: [NavList] Re: Bubble Sextant as Dip Meter
Brad you wroteI was reading HO551, Manual of Ice Seamanship.After a discussion of abnormal refraction and the care a navigator should take in regards to it, the following interesting statement is made"If the motion of the ship permits use of a bubble sextant, it can quickly be determined whether the apparent horizon is appreciably displaced"The manual gives no further information.
Am I to infer that a bubble sextant can be used as a dip meter. Or is it merely a gross check, as in 'the horizon is far from normal'.Has anyone tried this? Can a bubble sextant be used as a dip meter?