Reading Wind and Water Conditions

[Cacia]

I have this little pastime where I look out the window and try to read the ocean. Whitecaps, current, tide, and wind direction. I live on a hill. Then, I usually talk to boat captains during the day and they describe what it is like. I try and correlate it with what I am seeing.

I am interested in tips you have for reading these conditions.

Recently, this boat captain explained that the wind direction in the opposite direction from the current makes this little "chop" cats paw pattern. I think I am learning to see it.

Anybody who can describe ways to judge currents, tides ,wind, please share your knowledge. Divemasters must do this almost every day as they gauge a diver's ability and the divability of a site
Question? How do you gauge current strength in knots? Practically speaking...

 

[spectrum]

Never try to judge waves from a higher vantage point. They will be bigger than they appear from up on a hill. The same can be said once you swim out aways from shore.

A heavy wind from the shore can knock down the seas and make for beautiful skin-diving and shore diving conditions including better visibility.

I have found these to be true.

Pete

 

[Cacia]

You mean, the wind from shore opposes the onshore swell ? Cancels it out a bit?

 

[rockjock3]

You mean, the wind from shore opposes the onshore swell ? Cancels it out a bit?

It all depends. Most of the time I find Blowhole to be divable it is an incoming tide and an strong wind from the SW. If the tide shifts while you are out and this wind is blowing then you will get the washing machine effect that people talk about in the opening of the little cove there. My only experience with the Blowhole though is during the winter. I didn't get certified till late last year and haven't dove it in the summer yet.

 

[spectrum]

You mean, the wind from shore opposes the onshore swell ? Cancels it out a bit?

Yes

I remember one day in October of 2004 I wanted to go skin-diving soooo bad. The wind was howling from the NW at 20+mph at the house. The buoy conditions showed heavy seas I drove down to the beach and this spot that I like was almost like glass. When I made it out to the ledge it started to be another story. I have seen this time and time again.

The reduced turbulence lets the visibility rise as well. Now keep this in perspective Catherine, instead of 5-10 feet we may make it to 20 or even 30 feet!

Pete

 

[dpbishop]

Since I race yachts, I spend way to much time trying to read wind patterns on the water. If your viewing from a high vantage point as you say, you can gauge wind strength by the consistancy of the chop; in lighter winds there will be smooth patches and rough patches, in heavy winds it will be more consistent.

There are two types of wind that effect the near shore environment; gradient winds that are caused by the movement of air from a high pressure system to a low pressure system (prevailing winds) and sea/land breezes ( onshore/offshore) that are caused by the change in the temperature differential of the land & ocean. Since land heats up by day and cools at night, while the ocean stays more or less constant, the usual pattern is offshore at night and early morning, onshore as the day progresses. When these align with the gradient winds they reinforce each other, when the oppose they detract from each other. Sometimes, when the two winds are about equal in force, you will get a zone where they meet that has no apparent wind but has wave action, generated by the two forces in opposite directions, that will produce the washing machine effect.

If you have a couple of hundred bucks to blow on sunglasses, a pair of Kanons will make it easier to differentiate subtle differences in the texture of the water surface. I had a pair, due to an unusual alignment of an on the water victory, a birthday and a lot of free rum, but I accidently tossed them overboard during a race. I still haven't told my gf (who gave them to me) that they're gone.

 

[Rick Murchison]

Now you've opened a positively *huge* subject, Catherine! Seas vary hugely from place to place. An 8 foot sea where you are generally means a gentle rise and fall; in the Med or the Gulf 8 ft seas will beat you nearly to death. Breakers in the open water may or may not mean a whole lot in the Gulf, while if you get open water breakers around Hawaii you've got some *serious* waves. I've seen swells that look benign because they're so far apart put green water over the bow of an aircraft carrier, but the same swell wouldn't even effect a typical dive boat - but it would make one hell of a surge on the bottom in a hundred feet of water...
Very complicated, very interesting, very fascinating.
A worth study object, sea conditions
Rick

 

[Charlie99]

Question? How do you gauge current strength in knots? Practically speaking...

Gear up, jump in, hover motionless and watch the reef go by. 1 kt is 10' in 6 seconds. OH, you wanted to know BEFORE you jumped in!!! ???

If you see big current swirls behind nav buoys, or the mooring ball gets sucked under then you don't get in the water. Other than that, I'm clueless

 

[J.S. Ragman]

This post should be invisible. If it isn't, ignore it.
JS

 

[Epinephelus]

Current is really hard to judge on the surface unless you're anchored and can see something just under the surface going by. Any wind will impart "leeway" on anything floating that has any part of it sticking up above the surface, giving a false indication of the water's actual movement.
E