5 Myths About Altitude Diving in Colorado, Busted
Carolyn Bryan Aug 05, 2026
We've heard just about every misconception about altitude diving over the years, usually from divers who trained somewhere else and assumed Colorado diving works the same way. Here are the ones that come up most, and why they're wrong.
Myth: "Denver isn't high enough for altitude diving to matter"
Reality: it is. PADI defines altitude diving as anything above 1,000 feet, and Denver sits at 5,280 feet. Even Chatfield Reservoir, one of the lower local sites, is over 5,400 feet. There's no local dive site in the Front Range that falls below the altitude threshold. If you're diving in Colorado, you're altitude diving, full stop, whether the lake looks intimidating or not.
Myth: "If I stay within the no-decompression limits, I can't get bent"
Reality: staying within the tables reduces your risk, it doesn't eliminate it. Decompression sickness can still happen even on dives that technically stayed within no-stop limits, especially with a fast ascent, repetitive dives, cold water, or exertion, all of which describe a typical Colorado dive pretty well. Altitude training exists specifically to build in extra conservatism for these conditions, not because the standard tables are unsafe at sea level.
Myth: "My dive computer handles altitude automatically, so I don't need to think about it"
Reality: some do, many don't, and assuming yours does is a real risk. Some dive computers detect altitude automatically. Others need to be manually set, and if yours is locked to sea level mode, it can give you longer no-decompression limits than are actually safe for where you're diving. Checking your specific computer's altitude settings before your first Colorado dive isn't optional, it's basic dive planning.
Myth: "It's just a lake, so it's less serious than ocean diving"
Reality: cold, low-visibility, high-altitude diving arguably demands more skill than a warm, clear reef dive, not less. Cold water saps your circulation and adds to decompression risk. Limited visibility means more reliance on buoyancy control and navigation skills. Divers who train regularly in Colorado conditions often find warm, clear tropical water noticeably easier by comparison.
Myth: "I can dive in the morning and drive up to the mountains that same afternoon"
Reality: your body keeps off-gassing nitrogen for hours after you surface, and driving to higher elevation during that window works against you the same way ascending too fast underwater would. The general guidance is to wait at least 12 hours before heading above 8,000 feet after a single dive, longer after multiple or deeper dives. If your dive day includes a drive into the mountains afterward, plan the timing deliberately instead of assuming it's fine.
The short version
Altitude diving isn't dangerous, but treating it like sea-level diving is where divers get into trouble. A one-day Altitude Diver specialty course covers all of this: adjusted tables, computer settings, and dive planning for local conditions.
If you got certified somewhere else and are new to diving here, this is the specialty worth taking first.
Underwater Phantaseas is a PADI 5 Star IDC in Lakewood, CO. Call 303-988-6725 or check out our Altitude Diver course.
