Royal Navy rum was never more than 110 proof, usually 105 proof. It was cut four to one before serving. Everclear is 140 proof, I dare you to drink a jigger straight.
180 proof spirit is so anhydrous you would have trouble keeping it at that proof.
What gives navy rum its color and flavor? 180 proof spirit is going to be white.
I drink 1.5 litres of navy rum every two weeks have for years. Much of what passes for rum is just flavored spirit. I’d drink more but at 75 discretion is the better part of Valor. You want some navy rum? Try Woods Bros. 107 proof navy rum or some Pusser’s Gunpowder proof. Both were issue.
Their are some (just a few) authentic aged in the cask rums that are perhaps worth a a shekel or two more. Most are a lot of hype. Find a good basic brand and enjoy. Anything over 90 proof and you’re just showing off.
I dare you to drink a jigger straight.
180 proof spirit >
I have, home double distilled rum called “ Fine Wine,” ( British Guyana) , also makes an excellent burn for old fashioned Plum Pudding.
A jigger of that “fine wine” is the best thing for a cold or sore throat.Knocks it right out.
These days I usually sip Lambs Navy Rum, at 150 proof. Its good and does not cost an arm or a leg.