Nice lantern! Mine isn't a Perko but is put together the same way. Cptn Force is right... unscrews from the bottom. I didn't notice the pair of small rings near the bottom of the lamp to stabilize it if sending aloft.
I use mine as both a back-up for my
electric masthead anchor light and as a
deck lamp (
securly placed on the bridge
deck inside the cockpit) when I am away from the
boat at night and on a foggy night even when I'm aboard.
When using it as an anchor light I send it up via the main
halyard on a sennet staff... in my case a 4 ft. varnished oak stick. This can be a royal pita on a blustery night but once up with the
halyard tensioned it is pretty stable.
In the
cockpit at night it makes my boat easy to pick out and easier to find in a
fog... it is also a cheery thing to find burning away when I have to get up to check anchor/mooring lines etc.
Then again I've met those who find the idea of a lit anchor light aloft understandibly a bit unnerving (the same sensible folks who don't approve of Molly Bs wood-fired stove) Fire on boats... hmmm