Wave Height Calculations

Useful marine web sites
Post Reply
User avatar
GeoffSchultz
Posts: 1059
Joined: Thu Dec 04, 2008 8:39 am
Location: BlueJacket: Guatemala
Contact:

Wave Height Calculations

Post by GeoffSchultz »

Here's an interesting web site that contains a program that calculates wave heights given the wind speed, fetch distance and water depth. Note it utilizes meters/second, but you can just use knots/2 as a fairly good approximation.

http://woodshole.er.usgs.gov/staffpages ... MWave.html

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

User avatar
GeoffSchultz
Posts: 1059
Joined: Thu Dec 04, 2008 8:39 am
Location: BlueJacket: Guatemala
Contact:

Re: Wave Height Calculations

Post by GeoffSchultz »

Here are some other interesting facts that I discovered.

Wave_Speed (kts) = 3 x Wave_Period. Thus, the longer the period, the faster the waves move.

Waves move in groups with the highest waves in the center of the group. The speed of the group is 0.5 x Wave_Speed. The smaller waves in the back of the group grow and move to the middle and the middle waves move forward and shrink. Eventually the front waves end up at the back of the wave group.

10% of waves are 25-30% higher than the significant wave height.

Once an hour you can expect to see a wave 2x the significant wave height.

Chop describes waves with a period of 3-8 seconds.
Waves have a period of 9-12 seconds.
Ground Swell has a period of 13-15 seconds.
Strong Ground Swell has a period of 16+ seconds.

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

Post Reply