You open the sky-lounge humidor before a long lunch and the wrappers have split down their length like dried mud. The air conditioning has been running hard for a fortnight in the Caribbean, and nobody topped up the humidification. Every cigar in that box is now firewood, and some of them were the owner's personal stock.
Why the Yacht Fights You
A cigar is a piece of agricultural produce held in a narrow moisture window. Almost everything about a yacht pushes it out of that window.
- Air conditioning dries the interior aggressively. Saloon air can sit well below 50% relative humidity.
- Ambient swings: alongside in Sint Maarten the outside air may be 85% RH and 32°C; two hours later the guest is smoking on a chilly deck in a strong breeze.
- Heat from adjacent machinery, warm bulkheads, spotlights inside cabinetry and direct sun through glass.
- Motion: cigars rub, shift and bruise in a moving box; loose fittings rattle.
- Salt air and diesel exhaust taint tobacco, which absorbs odour readily.
- Neglect: humidors are checked when someone remembers, not on a schedule.
The Target Bands
Commonly cited storage targets are approximately:
| Parameter | Common target range | Comment |
|---|---|---|
| Relative humidity | roughly 68-72% RH | Some merchants prefer slightly drier, around 65%, especially for large ring gauges |
| Temperature | roughly 16-21°C (60-70°F) | Cooler is safer than warmer |
| Combined rule of thumb | "70/70" (70°F / 70% RH) | A memory aid, not a specification |
Treat these as a range, not gospel. The yacht's own humidor system, the manufacturer's instructions for that cabinet, and the advice of the cigar merchant who supplied the stock take precedence over any general figure. Record the band the yacht actually works to and stick to it.
What Goes Wrong Outside the Band
| Condition | Symptoms | Consequence |
|---|---|---|
| Too dry (below ~60% RH) | Cracked or splitting wrapper, brittle feel, fast hot burn, flavour lost | Often irreversible; re-humidify slowly, never quickly |
| Too humid (above ~75% RH) | Spongy feel, tight draw, cigar will not stay lit, sour smoke | Mould risk; wrapper may swell and split |
| Too warm (above ~22-24°C) | Oils sweat out; tobacco beetle risk rises sharply | Can destroy the entire stock |
| Fluctuating | Wrapper expands and contracts | Splitting and cracking even if the average looks fine |
Stability matters more than hitting an exact number. A humidor steady at 65% RH is healthier than one oscillating between 60% and 78%.
Siting the Humidor
- Away from air-conditioning outlets, hot bulkheads, engine-room boundaries and direct sunlight.
- Secured for sea, in a locker or cabinet that will not slam or slide.
- Accessible enough that the daily or weekly check actually gets done.
- Not in a place where a guest can leave the lid open — the single most common cause of a dried-out humidor.
Onboard Notes
Put the humidor check on the interior schedule as a named task with a named owner, and log the reading. "Someone will notice" is not a system.
Never try to rescue very dry cigars by soaking or by spiking the humidity. Rapid rehydration splits wrappers. Bring humidity up gradually over weeks, and accept that some stock will be lost.
If the stock is the owner's personal collection, tell the chief stew the moment you suspect a problem. Delay makes it worse and looks like concealment.