Algae bloom and visibility

[Purple Jos]

My question is… Is there a normal\average depth where an Algae Bloom lingers?
I was told by other divers that the norm for algae is to stay above the 15 foot mark. It’s not a fixed number, but more of an average.

The reason behind it is that I was at Redondo Beach on Saturday. We got in, went to 35 fsw and still had less the 5ft vis, and had not broken through the algae. It was low tide and the plan was to stay on the shallow side. I called the dive, my first time ever, and we went to a different site. The second site had more vis and more current, but overall a great dive. I was told by some divers in the area that the visibility was bad due to the Algae bloom. I have tried reading up on the subject, but I was not able to find a lot of info on how the bloom affects divers, and more how it affects humans, plant life and people on vacation.

I will say that my dive buddies were awesome. We drove 3 hours 1 way, and were underwater less than 6 minute, I was worried they would be disappointed, but the only thing they said was “Safety first, and you didn’t feel safe. No question, we end the dive.”

 

[MXGratefulDiver]

It was bad all the way down to 90 fsw on Monday ... although it cleared up a bit down deeper (from about 1 foot of vis at 20 fsw to about 5 feet of vis at 90 fsw). It really depends on conditions. We have a "perfect storm" for bad vis at the moment ... a mixture of plankton bloom, snowmelt, rain runoff, and rather large tidal activity.

That massive windstorm we had about 10 days ago didn't help either ... it's completely changed the bottom topography. The mudline at the entry's come up about a foot and a half, and even down deep it's moved the boats around and even filled the ladder boat (at 70 fsw) with mud and silt ... if the ladder weren't sticking out at the bow you wouldn't even know there was a boat there.

All of those factors are making for some of the worst vis I've seen in years.

I suspect your alternate site was Three Tree North ... which is much less silty due to a rockier terrain, consistent flow in one direction (toward the point) and less prone to spring runoff.

... Bob (Grateful Diver)

 

[Purple Jos]

We ended up going to Titlow Beach. It was recommended by employee at Underwater Sports on Federal Way. One of the employees dived there earlier in the day.
We were aiming for the slack current, but missed it, us and 8 other divers. It was still a really nice dive there.

Thank you for the information NWGratefulDiver. I appreciate it.

 

[TSandM]

It is pretty typical for the algae bloom to stratify, and often it will extend from the surface down to about thirty feet or so. But as Bob says, that's dependent on fairly calm water; anything that causes turbulence will also distribute the bloom. During these periods, it's generally reasonable to swim down a ways to see if there IS a bottom to the mess -- on Sunday, in Hood Canal, it was at 50 feet, but below that, we had probably 25 feet.

Algae blooms occur when the amount of daylight increases. They're cyclical; the algae grows like crazy, and then begins to die and coagulate into what some of us call "whale snot", which resembles long strings. Those will settle to the bottom, and we'll have a few days of superb viz before the next bloom gets going. If you hang out on our little local board (nwdiveclub.com) you'll see the excited reports showing up, "Great viz at xxxxx!" as we all urge folks to get out and dive while the diving's good.

This particular bloom is really nasty. I haven't seen viz this bad for several years.