Interpreting Buoy Station Info

[TheRedHead]

Hi Everyone,

I know I can access buoy station readings for all over the diving world, but I don't understand how to interpret the data for use in planning scuba trips. I don't even know what is helpful in the Marine Forecasts.

For example, how does this information relate to water conditions for scuba diving:

Station 41004
EDISTO - 41 NM Southeast of Charleston, SC
32.50 N 79.10 W

Latest Observation
Wind Direction (WDIR): --
Wind Speed (WSPD): --
Wind Gust (GST): --
Wave Height (WVHT): 5.91 feet
Dominant Wave Period (DPD): 10 seconds
Atmospheric Pressure (PRES): 30.16 inches
Pressure Tendency (PtdY): +0.6 (rising)
Air Temperature (ATMP): 77.54 °F
Water Temperature (WTMP): 77.54 °F
Dew Point (DEWP): --

Date/Time
(UTC) Wind
Direction
(º North) Wind
Speed
(m/s) Peak
Gust
(m/s) Wave
Height
(m) Wave
Period
(sec) Barometer
(mb) Air
Temp
(ºC) Water
Temp
(ºC) Dew
Point
(ºC) Pressure
Trend
(hPa)
9/23/2004 1600 hrs -- -- -- 1.8 10 1021.4 25.3 25.3 -- +0.6
9/23/2004 1500 hrs -- -- -- 1.8 10 1021.2 25.3 25.3 -- +0.4
9/23/2004 1400 hrs -- -- -- 1.7 10 1021.3 24.6 25.2 -- +1.0

In the marine forecasts, what the ideal wave height one looks for?

Tropical N Atlc From 7n To 22n Between 55w And 65w

This Afternoon
N of 19n W of 60w wind S 15 kt. Seas 9 to 12 ft in NW swell. Elsewhere N of 19n wind variable less than 10 kt. Seas 8 to 10 ft in NE swell. S of 19n wind se to S 10 kt. Seas 4 to 6 ft in N swell.
Tonight
N of 16n wind SW to W 10 to 15 kt. Seas 10 ft in NW swell W of 60w and 8 ft E of 60w. S of 16n wind E to se 10 kt or less. Seas 4 to 5 ft in N swell.
Fri
N of 17n W of 59w wind S to SW 10 kt or less. Seas 4 to 6 ft in N swell. Elsewhere N of 15n wind variable 10 kt or less. Seas 4 to 6 ft in N swell. S of 15n wind E to se 10 kt. Seas 4 to 6 ft in N swell.
Fri Night Through Sun
N of 18n W of 60w wind variable 10 kt or less. Seas 2 ft. Elsewhere wind N to NE 10 kt. Seas 4 to 6 ft.
Mon
Wind N to NE 10 kt or less. Seas 3 to 4 ft.

I would think that Monday looks best, but is 3 to 4 ft seas good diving conditions?

 

[matt_unique]

Hi Everyone,

I know I can access buoy station readings for all over the diving world, but I don't understand how to interpret the data for use in planning scuba trips. I don't even know what is helpful in the Marine Forecasts.

For example, how does this information relate to water conditions for scuba diving:

Station 41004
EDISTO - 41 NM Southeast of Charleston, SC
32.50 N 79.10 W

Latest Observation
Wind Direction (WDIR): --
Wind Speed (WSPD): --
Wind Gust (GST): --
Wave Height (WVHT): 5.91 feet
Dominant Wave Period (DPD): 10 seconds
Atmospheric Pressure (PRES): 30.16 inches
Pressure Tendency (PtdY): +0.6 (rising)
Air Temperature (ATMP): 77.54 °F
Water Temperature (WTMP): 77.54 °F
.....
Mon
Wind N to NE 10 kt or less. Seas 3 to 4 ft.

I would think that Monday looks best, but is 3 to 4 ft seas good diving conditions?

Buoy data - useful to tell you what is going on 30 minutes ago (depending upon how often they are updated). It helps to know what the water temp is (showing you surface water temp of course, not what you will experience at depth) and the wind speed. The wave period if the amount of time from one wave peak to the next. The longer the wave period the better (usually) because it means the waves are farther apart. There is a lot of other data that will not be as readily useful to you.

The marine forecast is most useful. Marine forecasts are usually more accurate than other forecasts (in my experience) but when it comes to the ocean never rely on an extended forecast I use the marine forecast for 48 hours max. Even in that time period the marine conditions can change a lot. I don't go out to dive in seas bigger than 2-4 feet or winds greater than 10-15 kts. When you see something like "wind SW at 15-20 kts" it means relative to the area you are looking at, the winds will be blowing out of the SW. So if you were there in your boat with a heading of SW on your compass you would be heading straight into the wind. I find that winds greater than 10-15 kts or seas larger than 2-4 feet make the boating/diving experience less comfortable/enjoyable. Everyone will have their own tolerance though.

What is really important is the shape of the waves and the wind. The stronger the wind the more likely the waves will be "sharp", steep, white caps, dangerous, etc. Swells are generally rounded waves. You can be out on a boat in 8' swells and it is no big deal - it's like going up and down an elevator. If you are diving from shore it will be different. Even swells when they crash to shore can cause lots of current, mixing bowls, etc.

Of course wave capacities will also depend on the boat you are in. I have a 19' boat. The biggest seas I have been in was 6' with strong winds. My buddies were grabbing the ceiling when we went over a wave because of how far we would "fall" off the wave, water was running over the cabin and windshield from spray and dipping into the water. I did not remain in these seas for long. I have also been in 8-10' swells that were rounded and quite a distance apart so they were no big deal.

--Matt

 

[DandyDon]

You can call for those on the phone, too, if you have the station number. (228) 688-1948. I'll load that, the prompts, and the station number in my cell phone for a trip.

Most stations give you wnd speed, but that one does not. Some don't surface water temp, but this one does. I'd wear a 5 mil long and a 2 mil beanie.

6 foot waves would mean a bumpy ride even in a big boat and challenges exiting the water for a newbie. I've done 8-12s, and that's my limit, but many captians won't go out in 8-12s, anyway. Yeah, 3-4 feet would be a much better day.

 

[TheRedHead]

:bawling:

You can call for those on the phone, too, if you have the station number. (228) 688-1948. I'll load that, the prompts, and the station number in my cell phone for a trip.

Most stations give you wnd speed, but that one does not. Some don't surface water temp, but this one does. I'd wear a 5 mil long and a 2 mil beanie.

6 foot waves would mean a bumpy ride even in a big boat and challenges exiting the water for a newbie. I've done 8-12s, and that's my limit, but many captians won't go out in 8-12s, anyway. Yeah, 3-4 feet would be a much better day.

3-4 feet sounds better, but a wave interval of 10 seconds, is that too much?

I was thinking about it in terms of where can I fly for $200. I can usually fly to Miami for $200 non-stop using Priceline. So, if I can read these thing 2 to 3 days in advance with any degree of accuracy, I would feel better about flying down to Florida for a dive weekend. It would be no fun to fly down and sit in a hotel for 2 days. It seems that you may have nice enough weather, but still marginally diveable conditions. I know there must be way to glean something from the Net or Dial a Buoy that is useful.

Cold weather is coming....:bawling:

 

[DandyDon]

Here's the Florida map link: http://www.ndbc.noaa.gov/Maps/Florida.shtml

And here's Molasses Reef Buoy, Key Largo: http://www.ndbc.noaa.gov/station_page.php?station=MLRF1

Today:

Wind Direction (WDIR): NE ( 50 deg true ) A due north wind is best there, as the key breaks it a bit. The waves don't have as far to build.

Wind Speed (WSPD): 18 kts Most skippers there won't go out in 20 kts, except for Silent World - then you just wish they hadn't.

Wind Gust (GST): 20 kts

Atmospheric Pressure (PRES): 29.91 in

Pressure Tendency (PTDY): -0.02 in ( Falling ) Not good

Air Temperature (ATMP): 82.4 °F Nice

Water Temperature (WTMP): 84.2 °F Very nice!

Salinity (SAL): 35.43 Ocean's still salty


If you go, put this in speed dial on your cell-phone: 2286881948 (wait) 1 (wait) 65731# (wait) 1. Do not hit the next prompt until the computer says to; can't rush it."To enter a station identifier, press 1" Then 1 "After your input, key the # sign" Then 65731# "You entered MLRF1; to confirm 1" Then 1

I call it just for fun some days, to see how nice it may be there. almtree:

 

[Wijbrandus]

:bawling: Cold weather is coming....:bawling:

Sounds like a good time to get that dry suit experience.

My wife and I are taking our dry suit specialties this winter because we don't want to wait for next summer to dive again.

 

[TheRedHead]

Thanks, everyone. Dandydon, you are so smart about these things and I appreciate the Keys wind info. Can you suggest any good books about maritime weather and possibly small boats?

Robert, I would probably enjoy dry suit diving, but the closest dive spot for me is in Alabama, 200 miles away. It is a private quarry that closes on October 31st. Everyone in the South just goes further south in the winter. The local LDSes all offer trips all winter long. These are usually longer trips than I can make.

I'm thinking seriously about buying a trailer camper just to use for weekend dive trips.

 

[DandyDon]

Thanks, everyone. Dandydon, you are so smart about these things and I appreciate the Keys wind info. Can you suggest any good books about maritime weather and possibly small boats?

Well, you're welcome, but I wouldn't go so far as to use the word smart. Key Largo is one of my favorite dive locations, and I know a bit about it. Maybe not as much as I think I know, but some. Certainly my fav place to refer a newbie, for a number of reasons.

I'm thinking seriously about buying a trailer camper just to use for weekend dive trips.

Boy, that'll tie you to your local quaries. Anywhere I can pull a trailer, I can usually find a decent room for $50 a night. For the trailer, you'd have tires, bearings, tags, etc. for the trailer; extra transmission, oil, gas, and tire costs for the pickup; and camping fees, if you stayed in a place that single woman would probably be safe in a trailer. Have to like quary diving a lot. I like shopping for cheap tickets, diving the St.Lawrence in Sept, North Carolina in Oct, Key Largo in Nov, and the Bahamas in Dec. Yeah, it costs more than a trailer and a local practice pit, but that's how I like to spend my money.

 

[outlawaggie]

:bawling:

3-4 feet sounds better, but a wave interval of 10 seconds, is that too much?

:

10 seconds is actually a short interval...a longer wave interval is better. a short interval means the wave a closer together and therrefore steeper so you bump up and down. a longer interval means the waves are long and gentle. I've been in the Pacific in 10' swells but the interval was so long that you only noticed them by watching the horizon. At the same time I've been in 10' in the Gulf and thought I was going to die.

Also, I have found that the bouy's are usually a foot or so off on the wave reporting. 3-4 by bouy is not a comfy ride.

 

[TheRedHead]

Boy, that'll tie you to your local quaries. Anywhere I can pull a trailer, I can usually find a decent room for $50 a night. For the trailer, you'd have tires, bearings, tags, etc. for the trailer; extra transmission, oil, gas, and tire costs for the pickup; and camping fees, if you stayed in a place that single woman would probably be safe in a trailer. Have to like quary diving a lot. I like shopping for cheap tickets, diving the St.Lawrence in Sept, North Carolina in Oct, Key Largo in Nov, and the Bahamas in Dec. Yeah, it costs more than a trailer and a local practice pit, but that's how I like to spend my money.

I have a hubby (who dives) and 2 teenagers who don't. I don't have a pickup; we have an Infinity and a Pontiac Bonneville and I'm not sure if I can pull a trailer with them. We took our 2 kids to St. John last year and I don't even want to think about how much it cost. We can drive to Florida in 12 hours. That would work for a week long vacation, but I have to see about how much it will cost vs. hotels.

Then again, if we fly to Florida, we can justify leaving the kids here....

I'm heading out the door to go diving in Huntsville.