Scuba diving burns between 300 and 700 calories per hour, with the wide range depending on water temperature, current strength, and how hard you’re working underwater. A relaxed boat dive in warm tropical water sits at the lower end (around 300 calories per hour), while a shore dive in cooler, temperate water can push closer to 600 calories per hour. That puts scuba diving roughly on par with jogging at a moderate pace.
How the Estimates Break Down
The Compendium of Physical Activities, which researchers use to standardize exercise intensity, assigns scuba diving a metabolic equivalent (MET) value between 5.3 and 7.0 depending on effort level. A MET of 1.0 is what your body burns at rest, so a MET of 7.0 means you’re burning seven times your resting rate. For a recreational diver specifically, the compendium lists a MET of 6.8.
To translate that into calories, you multiply the MET value by your weight in kilograms and the number of hours. A 155-pound (70 kg) recreational diver would burn roughly 476 calories in one hour at a MET of 6.8. A 200-pound (91 kg) diver doing the same dive would burn around 619 calories. Lighter effort drops the MET to 5.3, which for that same 155-pound person works out to about 371 calories per hour.
Why Water Temperature Matters So Much
The single biggest variable in how many calories you burn on a dive is water temperature. Water conducts heat away from your body about 25 times faster than air does, and your metabolism has to ramp up to compensate. This isn’t just a minor adjustment. A study published in the National Institutes of Health examined military divers during a six-hour cold-water training dive and found a 53% increase in energy expenditure compared to pre-dive levels. Their metabolic rate jumped from about 1.9 calories per minute at rest to 2.8 calories per minute during the dive.
What’s especially interesting is where that extra energy came from. The increase was driven almost entirely by fat burning, not carbohydrate use. Fat oxidation nearly doubled, going from 0.07 grams per minute before the dive to 0.13 grams per minute afterward. Carbohydrate utilization stayed roughly the same. So cold-water diving doesn’t just burn more calories overall; it preferentially taps into fat stores to generate heat.
This explains the gap between PADI’s estimates: a shore dive in temperate water (roughly 60°F/15°C) burns about 600 calories per hour, while a leisurely boat dive in warm tropical water (80°F/27°C) burns closer to 300. Even with a wetsuit providing insulation, your body still works significantly harder to maintain its core temperature in cooler water.
Other Factors That Raise or Lower the Burn
Beyond temperature, several things shift your calorie expenditure on any given dive:
- Current and conditions. Swimming against a current requires sustained effort from large muscle groups in your legs and core. A drift dive where the current does the work for you burns far less than fighting surge or swimming to a distant reef.
- Body size. Larger individuals burn more calories both because they have more mass to move through water and because they lose heat faster due to greater surface area.
- Experience level. Newer divers tend to burn more calories than experienced ones. Inefficient fin kicks, poor buoyancy control, and general tension underwater all increase energy expenditure. As your skills improve, you become more streamlined and relaxed, which actually lowers the calorie burn per dive.
- Depth and gear. Deeper dives often involve heavier gear, more lead weight, and denser breathing gas, all of which add to the physical workload. Shore entries that require walking across a beach in full gear also front-load extra effort before you even get in the water.
Scuba Diving Compared to Other Activities
At a MET of 6.8 for recreational diving, scuba falls in a similar intensity range as hiking with a pack (6.0-7.0), cycling at a moderate pace (6.8), or swimming leisurely laps (6.0). It sits well above walking (3.5) and below running at 6 mph (9.8). The key difference is that diving doesn’t feel as physically intense as those numbers suggest, because much of the calorie burn comes from thermoregulation rather than muscular effort. You can finish a dive feeling cold and tired without ever feeling like you “worked out.”
Fueling for a Dive Day
Because scuba diving burns more calories than most people expect, nutrition matters, especially on multi-dive days. Recommendations from the Naval Medical Research Institute suggest recreational divers consume 40 to 50 calories per kilogram of body weight on a day involving three hours of diving. For a 155-pound person, that’s roughly 2,800 to 3,500 calories for the full day.
The recommended breakdown leans carbohydrate-heavy: about 50% of your calories from carbs, less than 30% from fat, and enough protein to hit at least 1 gram per kilogram of body weight (roughly 70 grams for a 155-pound diver). Carbohydrates are especially important because they fuel the sustained, moderate-intensity effort of finning and help prevent the fatigue and mental fog that can make diving less safe. Eating a solid meal two to three hours before a dive, and snacking between dives on a multi-dive day, helps maintain energy without causing discomfort underwater.