Glacier Bay Watercraft Noise
Kipple B and Gabriele C. 2003. Glacier Bay Watercraft Noise. Technical Report. NSWCCD-71-TR-2003/522. Naval Surface Warfare Center, Carderock Division - Detachment Bremerton. Bremerton, WA
Underwater noise levels of 14 vessels operated by Glacier Bay National Park and Preserve were measured in 2000 and 2002. The vessels tested were from 14 to 65 feet in length and engine power ratings ranged from 25 to 420 horsepower. Most boats were evaluated at speeds of 10, 14, and 20 knots. These watercraft generated peak one-third octave noise levels ranging from 150 to 177 dB re 1 microPa at 1 yard and sound levels from 157 to 181 dB re 1 microPa at 1 yard. Noise levels depended on vessel type. All vessels but one, the 65 foot Nunatak, were classified as small craft with high-speed engines. As a group, skiffs under 20 feet in length and 100 horsepower produced the lowest sound levels, followed closely by the jet powered craft, which were the largest and highest powered small craft that were evaluated. Propeller powered small craft with engine power ratings over 100 horsepower produced the highest noise levels. Nunatak's noise levels were lower than those produced by many of the over 100 horsepower propeller driven group. Noise levels also depended on vessel speed. On the average, vessel sound levels were about 4 dB greater at 20 knots compared to 10 knots. However, increases of up to 6 dB were observed for some vessels over this speed range. In comparison with noise levels from large cruise ships, the small craft one-third octave noise levels were generally lower at lower frequencies. However, in some bands at frequencies above 1 kHz, the small craft noise levels were comparable to, or in some cases greater than, cruise ship noise levels.
- Type
- Published Report
- Authors
- Kipple, Blair; Gabriele, Chris
- Date of Issue
- 2003-02
- Publisher
- Naval Surface Warfare Center, Carderock Division - Detachment Bremerton
- Units
- GLBA
- Keywords
- Bioacoustics, Recreation, Soundscape