Saltair
Contributor
I posted here a couple days back about kicking in silt. I was back in that harbor today looking for a guys mooring, it was cut off by ice over the winter, and if I thought it was bad before I was wrong. I dont have a lot of dives, 25 or so, all in the ocean. What I saw today maybe common in lakes, but I had not run across it before, and was somewhat surprised by it. There were sratified layers of silt in the water column that created the illusion of being at the bottom. The actual water depth was only 14 or 15 feet. Surface Vis wasn't great, but not bad for around here, but as we approached the 1st layer at about 8 feet there was a dramtic drop in vis, and then from about 10 or 11 feet to the bottom there was a suspended sediment that reached all the way to the bottom making it essentially invisible. It was very hard not to swim into it which of course took limited vis down to zero, but once suspended above it you had to be only inches from the bottom to be able to see it, and I could only see the bottom for maybe two feet in either direction. My wife was with me swimming above and to my left and if I turned to look at her I could only see her mask and hand holding her console, but I could reach out and touch her. She said she never saw the bottom. She was not happy with the conditions at all. I found the whole thing somewhat unsettling at first then just marveled at how miserable it was. The interesting thing is there is a fairly significant tidal current here. There is a salt marsh at the head of the harbor that empties completely at low water. The tide had been running out for a couple hours when we started, and there was a definate temperature drop about the time you swam through the first layer. The current at the bottom is much weaker than at the surface. My theory on this is the warmer water from the harbor and marsh was running out over the top of the colder water from the bay, and the sediment layer at about 8' was at that boundry. What I cant explain is the suspended particles at the bottom. I have been in this harbor all spring, but have not run accross this. I would say I should dive it before the tide changes, but will that eliminate the crap at the bottom? It was very windy here last sunday, but has been pretty typical since and there has been no rain. I am looking for explanations that may make my diving more effectice and suggestions on how your supposed to find anything in conditions like that. Other than dumb luck I guess.
Sorry about the typos its getting late, but I wanted to throw this out while it was fresh in my head...
Sorry about the typos its getting late, but I wanted to throw this out while it was fresh in my head...