Douglas sea and swell scale
Table
sea swell
low moderate heavy
no short or long short average long short average long confused
swell average swell
0 1 2 3 4 5 6 7 8 9
0 calm 00 01 02 03 04 05 06 07 08 09
1 smooth 10 11 12 13 14 15 16 17 18 19
2 slight 20 21 22 23 24 25 26 27 28 29
3 moderate 30 31 32 33 34 35 36 37 38 39
4 rough 40 41 42 43 44 45 46 47 48 49
5 very rough 50 51 52 53 54 55 56 57 58 59
6 high 60 61 62 63 64 65 66 67 68 69
7 very high 70 71 72 73 74 75 76 77 78 79
8 precipitous 80 81 82 83 84 85 86 87 88 89
9 confused 90 91 92 93 94 95 96 97 98 99