How loud is a jet ski under water?
Under water, jet skis recorded in Queensland had source levels of 122 to 149 dB re 1 µPa at 1 m, with a median of 137 dB. These underwater figures use a different reference pressure from sound in air, so they are not comparable with the dBA figures elsewhere on this scale.
- Level
- 122–149 dB re 1 µPadecibels relative to 1 micropascal, measured in water
- Distance
- 1 m1 m (source level, back-calculated)
- Daily limit
- Underwater levelnot an air level
What the numbers mean
How it was measured. Broadband monopole source levels of personal watercraft recorded under water in Bramble Bay, Queensland: 122, 137 and 149 dB re 1 µPa at 1 m (5th, 50th and 95th percentiles). Underwater decibels use a different reference from airborne decibels and cannot be compared directly.
The recordings were made in Bramble Bay, Queensland. Most of the underwater sound came from the vibrating cloud of bubbles in the jet stream, spread between 100 Hz and 10 kHz, overlaid with tones from the impeller blades. The 5th, 50th and 95th percentile source levels were 122, 137 and 149 dB re 1 µPa at 1 m.
The study found these levels were lower than those of small propeller-driven boats, but pointed out that the broadband level is not necessarily what matters for marine animals; the character of the sound and how often it occurs also count.
Is it dangerous?
Measured in water against a 1 µPa reference, so the number cannot be compared directly with levels in air. See the underwater note on the Scroll. Marine-mammal and diver exposure criteria use their own metrics and are outside the scope of this page.
Protecting your hearing
Above water, riders and swimmers nearby are mainly exposed to engine and hull slap noise; earplugs designed for water sports help riders. Keep jet skis away from swimmers and wildlife areas.
Questions
How loud is a jet ski under water?
Source levels of 122 to 149 dB re 1 µPa at 1 m, median 137 dB, were measured in Queensland.
Can I compare this with dBA in air?
No. Underwater decibels use a reference of 1 µPa rather than the 20 µPa used in air, and water carries sound differently.
Sources
- Underwater noise of small personal watercraft (jet skis), Journal of the Acoustical Society of America (Erbe, 2013), abstract via Europe PMC. Supports: dB_low 122, dB_high 149 dB re 1 µPa at 1 m.
Broadband monopole source levels were 149, 137, and 122 dB re 1 μPa @ 1 m (5th, 50th, and 95th percentiles).
Checked 2026-11-03. - Underwater noise of small personal watercraft (jet skis), Journal of the Acoustical Society of America (Erbe, 2013), abstract via Europe PMC. Supports: sound source description.
Underwater noise emissions consisted of broadband energy between 100 Hz and 10 kHz due to the vibrating bubble cloud generated by the jet stream
Checked 2026-11-03. - Underwater noise of small personal watercraft (jet skis), Journal of the Acoustical Society of America (Erbe, 2013), abstract via Europe PMC. Supports: comparison with propeller boats.
Even though these are lower than those of small propeller-driven boats
Checked 2026-11-03.
This page is general information, not medical advice. If you have ringing in your ears, muffled hearing or any change in your hearing, see an audiologist or your doctor.