BigBill, I think you are correct. However, what has me puzzled is the Moon Altitude correction table tells you to take the average of the upper and lower limb shots and then subtract 0° 15' which I assume is a rough figure for the Moon's semi-diameter.
A good way to test this idea is to take a series of sights of the moon spacing them over a period of a few hours. Then use the Moon Altitude correction tables and apply it to the Hs (plus or minus IE). The result will be Ho as I'm sure you know already. But when comparing the resulting Ho to Hc you'll get a series of plots that, if the above assumptions are correct, will give you a good series of LOPs and hopefully a good fix of a known Longitude and Latitude (your deck). If the LOPs appear to be off by the SD of the moon or the 15 minute subtraction they tell you to use then you'll know, to correct the previous sights, you'll have to subtract the 15'.
Shooting the moon over the ocean is easy. Shooting the Moon using an AH is easy but I've never used a bubble sextant. Regardless, my corrections for a Moon sight Lower Limb are as follows when using an AH;
Ha= Hs -/+ IE
Ho= Ha + Moon Correction
Roland
A good way to test this idea is to take a series of sights of the moon spacing them over a period of a few hours. Then use the Moon Altitude correction tables and apply it to the Hs (plus or minus IE). The result will be Ho as I'm sure you know already. But when comparing the resulting Ho to Hc you'll get a series of plots that, if the above assumptions are correct, will give you a good series of LOPs and hopefully a good fix of a known Longitude and Latitude (your deck). If the LOPs appear to be off by the SD of the moon or the 15 minute subtraction they tell you to use then you'll know, to correct the previous sights, you'll have to subtract the 15'.
Shooting the moon over the ocean is easy. Shooting the Moon using an AH is easy but I've never used a bubble sextant. Regardless, my corrections for a Moon sight Lower Limb are as follows when using an AH;
Ha= Hs -/+ IE
Ho= Ha + Moon Correction
Roland