I am planning a circumnavigation, westbound, starting from Panama. My boat, Islander, has a magnetic compass in the binnacle. To date, I have cruised only in the northern hemisphere. I understand that when cruising in the southern hemisphere, one needs a southern hemisphere compass. How do cruisers handle this? Do you use a handheld southern hemisphere compass? Other suggestions, solutions? Thanks for your ideas.

Barbara.Euser - 7 Feb 2021

I am planning a circumnavigation, westbound, starting from Panama. My boat, Islander, has a magnetic compass in the binnacle. To date, I have cruised only in the northern hemisphere. I understand that when cruising in the southern hemisphere, one needs a southern hemisphere compass. How do cruisers handle this? Do you use a handheld southern hemisphere compass? Other suggestions, solutions? Thanks for your ideas.

I simply used the Plastimo compass that came with my boat when I went to the southern hemisphere.  I think most cruisers from the northern hemisphere just use the same compass in the southern hemisphere.  The compass may have been slower to react in the southern hemisphere, but I don't remember that being very noticeable--it seemed to work about the same in both hemispheres.  

If you can find a manual for your particular compass it would be worth seeing what it says about using it in the southern hemisphere. 

Richard

Barbara.Euser - 7 Feb 2021

I am planning a circumnavigation, westbound, starting from Panama. My boat, Islander, has a magnetic compass in the binnacle. To date, I have cruised only in the northern hemisphere. I understand that when cruising in the southern hemisphere, one needs a southern hemisphere compass. How do cruisers handle this? Do you use a handheld southern hemisphere compass? Other suggestions, solutions? Thanks for your ideas.

I think the issue with southern hemisphere compasses is about the angle of inclination. But this is only an issue with a flat, hand-held compass (such as the Silva type) when the needle grounds on the casing. I don't think it's an issue in a marine, binnacle type compass where the card moves in all planes. 
I think that's right but I'm no expert and am happy to be corrected.

Simon