How can I predict good/bad Visibility??

[Ride_or_Dive]

Hey guys, long time lurker but first time poster. I've been diving since I was 13, all over Florida, the Caribbean, and even Asia. I just picked up spearfishing, and I'm already hooked, even though I haven't taken anything home yet! :cussing:

Recently ( <2 yrs) I've been shore diving off of the treasure coast, which stretches from Sebastian to Vero Beach. I like this diving because it is closer to me, and its free! What I've found is some days the vis is decent, and some days its absolute crap. Like where you are just crawling around on the bottom, hoping that maybe there are some bugs, but you can't see more than 3 feet.

I try calling the local shops, but nobody seems to know what the vis is. I looked but I can't seem to find any kind of "vis report".

1) Is there a "vis report" for this area?
2) What can I do to help predict the vis?

Thanks in advance for the replies. Bug season is almost over, so I'm planning on hitting up some spots this weekend, visibility permitting. I'll see you out there!

 

[jimw]

NDBC - Station 41114

This is the NOAA buoy NE of the Ft Pierce Inlet. I use the water temp and wave height as well as the wave period info. Winds out of the west are beneficial as they flatten waves and improve viz for dives at Pepper Park north of the inlet. There is a phone at the lifeguard stand there as well. The longer the period of the waves the better. If you get winds out of the west for a couple days and a longer period in the 10 second or higher range--viz will be ok!

I think there is a buoy near Sebastian too, you might find more using the nearby buoys link on the site........

 

[Ride_or_Dive]

NDBC - Station 41114

This is the NOAA buoy NE of the Ft Pierce Inlet. I use the water temp and wave height as well as the wave period info. Winds out of the west are beneficial as they flatten waves and improve viz for dives at Pepper Park north of the inlet. There is a phone at the lifeguard stand there as well. The longer the period of the waves the better. If you get winds out of the west for a couple days and a longer period in the 10 second or higher range--viz will be ok!

I think there is a buoy near Sebastian too, you might find more using the nearby buoys link on the site........

Thank you, that is awesome information. The only problem is I have no idea how to identify a long period of waves, wave height, etc because I have nothing to compare them to. I can't figure out how to get historical data from that website. Also, do you mean there is a direct line to every lifeguard post?

 

[jimw]

This morning, wave height is reported by the buoy as 5.2 ft. The buoy is in about 50 ft of water. 5 ft is not good, I look for 1 or 2 ft. The longer the period of the waves, the better; as it feels like a more gentle motion. Look for a period of 10 seconds or longer. This morning's period is 6 seconds and along with 5 ft seas=surge, discomfort and lousy viz!

Also, sustained winds out of the west are essential. Look for a couple days of westerly winds FIRST!

 

[tursiops]

This morning, wave height is reported by the buoy as 5.2 ft. The buoy is in about 50 ft of water. 5 ft is not good, I look for 1 or 2 ft. The longer the period of the waves, the better; as it feels like a more gentle motion. Look for a period of 10 seconds or longer. This morning's period is 6 seconds and along with 5 ft seas=surge, discomfort and lousy viz!

Also, sustained winds out of the west are essential. Look for a couple days of westerly winds FIRST!

In general, jimw's physics might be a bit confused. The longer-period waves also reach farther down into the water column, so have more chance of disturbing the bottom and thus the viz. A ten-second wave is about 150m crest to crest, so easily reaches down about a third of that distance, or 50m; even if you argued only a tenth of the water column is disturbed, that's 15m or 50 ft. If the depth is 50 ft, there *will* be surge on the bottom and sediment stirred up, in general. The other factor, of course, is the wave height. Higher waves proportionally disturb the water column more, and the bottom too if the motions reach to the bottom. So worst of all is long-period, high waves. Best of all is short-period, low waves. In between -- short-period high waves or long-period low waves -- it depends on the details. jimw argues 6-sec waves with 5-ft heights are bad. A 6-sec wave has a crest length of about 54m, and a third of that is 18m, so will reach that 50-ft bottom with some decent surge and viz reduction. But the same effect could happen with a longer wave with a shorter period. My guess is, in jimw's locale and experience, the 10-s waves are "always" small, so the reduction in wave height "always" compensates for the greater depth-reach of those longer waves. In general, however, this is not true, and just because a wave is longer doesn't mean you can count on better viz...in fact, usually a longer wave means worse viz.

The winds from the west are the best clue to good viz, in that location. It means a short fetch over which the wibnd blows, so less chance for growth of the waves and no chance for long waves. Short waves, low waves = good!

 

[Ride_or_Dive]

Thanks guys, I really appreciate your replies. I did just talk to a former professor and he confirmed what you all were saying. Looks like NE winds for the past few days, along with 5ft wave height, means no diving

Edit: For anyone reading this thread, the Sebastian buoy can be found here, though it does not record wind data:
NDBC - Station SIPF1

 

[Scuba_Jenny]

Good stuff. thanks for the info..

 

[jimw]

Tursiops,

When shore diving Pepper Park north of Ft Pierce, FL on the east coast, winds out of the west and long period waves mean less wave action at the entry, so the dive is easier with flatter seas and greater viz. Does that make sense? The depth there is in the 20 ft range. My main key though is wind out of the west which flattens seas and allows for the best viz possible.