Office (401) 921-5170         
Fax (401) 921-5159         
 

Pierson - Moskowitz Sea Spectrum
- Values are worst case forecasts for open water in vicinity of referenced point

Wind Speed (Kts) Sea State Significant Wave (Ft) Significant Range of Periods (Sec) Average Period (Sec) Average Length of Waves (FT)
3 0 <.5 <.5 - 1 0.5 1.5
4 0 <.5 .5 - 1 1 2
5 1 0.5 1 - 2.5 1.5 9.5
7 1 1 1 - 3.5 2 13
8 1 1 1 - 4 2 16
9 2 1.5 1.5 - 4 2.5 20
10 2 2 1.5 - 5 3 26
11 2.5 2.5 1.5 - 5.5 3 33
13 2.5 3 2 - 6 3.5 39.5
14 3 3.5 2 - 6.5 3.5 46
15 3 4 2 - 7 4 52.5
16 3.5 4.5 2.5 - 7 4 59
17 3.5 5 2.5 - 7.5 4.5 65.5
18 4 6 2.5 - 8.5 5 79
19 4 7 3 - 9 5 92
20 4 7.5 3 - 9.5 5.5 99
21 5 8 3 - 10 5.5 105
22 5 9 3.5 - 10.5 6 118
23 5 10 3.5 - 11 6 131.5
25 5 12 4 - 12 7 157.5
27 6 14 4 - 13 7.5 184
29 6 16 4.5 - 13.5 8 210
31 6 18 4.5 - 14.5 8.5 236.5
33 6 20 5 - 15.5 9 262.5
37 7 25 5.5 - 17 10 328.5
40 7 30 6 - 19 11 394
43 7 35 6.5 - 21 12 460
46 7 40 7 - 22 12.5 525.5
49 8 45 7.5 - 23 13 591
52 8 50 7.5 - 24 14 655
54 8 55 8 - 25.5 14.5 722.5
57 8 60 8.5 - 26.5 15 788
61 9 70 9 - 28.5 16.5 920
65 9 80 10 - 30.5 17.5 1099
69 9 90 10.5 - 32.5 18.5 1182
73 9 100 11 - 34.5 19.5 1313.5

table from Resolute Weather rw.gif (5253 bytes)