Freshwater dive

[kurtisenbecker]

I have about 75 dives under my belt right now but I am about to dive a fresh water lake for the first time. I am aware that there will be lower temperatures (thermolclines), more chance of entanglements (fishing lines...), reduced visibility (silty bottoms) and of course the dramatic difference in buoyancy. I realize that the density of one cubic feet of fresh water compared to salt water is about 2lbs so you will be negatively buoyant. I will reduce my weight by about 4-7lbs in order to compensate as well as do a buoyancy check before I start my dive. The final thing I will consider is the altitude of the lake itself so I can make adjustments on my dive tables (is there dive tables available online that already has this info?).


What I would like to know is: have I considered all the aspects of this dive from a safety perspective? If not, what am I missing? Also, does anyone have any extra advice? What about using Nitrox?


Thank you

 

[drrich2]

How deep do you plan to go, how long do you plan to stay down, will you dive solo or with a buddy, how seasoned is the buddy, is this a lake & area of that lake known to be a good diving spot or are you just jumping in a place hoping to get lucky, and are currents an issue at this lake? Will you be diving in an area boats go through? Have you towed a dive flag before? If local boaters don't know what a dive flag is, they might actually head to it to see what it is.

Richard.

 

[ZzzKing]

Around here, the jet skis use the flag as part of a slalom course.

The dive part will probably be darker, less colorful and colder than most saltwater diving but other than dropping 5 or 6 pounds, you should be good.

 

[mi000ke]

Yeah - power boats and jet skis to me are the biggest hazard, especially if it's a popular boating lake. I used to have a place on a popular lake in Maine, and even going out kayaking was like taking my life in my hands, especially on weekends. Seems like once a week some drunk yahoos would be motoring their boats or jet skis into people, docks, or each other, and they never respected the buoy lines that people laid out to keep them away. So watch out.

 

[Texasguy]

Ok, my turn.

Everything will be more slippery, slimy. Might want to wear thin gloves, at least, if you are planning to touch things. Fresh water fish can come for your ears or other open pale skin parts, wear a hood of sorts. Have a flashlight and a backup. Be comfortable to be in zero visibility, assent only by looking at your depth gauge. Your gear might smell afterwards, depending how swampy was the water. Probably you want as little as possible of the water getting into your mouth, more bacteria. Watch out for gators, snakes, and snapping turtles. Bullsharks can swim in fresh waters too. Watch out for anything rusty.

 

[Jim Lapenta]

Any place where there are power boats and jet skis I carry a length of floaty nylon rope. Should they get too close to the flag, just let it go. Good for fouling props and intakes.

 

[NorCalDM]

You mentioned altitude this would be one of the main factors to me. What is the altitude and are you trained for it? Diving at a higher altitude is not the same as diving at sea level and if you don't know what you are doing you can get yourself hurt.

 

[k ellis]

I am just an old diver who enjoys the sport so when I am not divemastering I enjoy diving in local lakes. One thing about our area lakes are they are all man made for the most part.

When you deal with man made lakes you can often find a treasure trove of history in them such as one of my favorite dive spots called the foundation. According to the locals there was a home that sat on top of a hill overlooking the river channel with some bluffs not far from it. When they built the lake they tore the home down but left the foundation.

Kind of neat to dive over a huge square of cement and see some steps from what used to be the front door.

In other instances there are things down there like old wagon wheels and many more historical items. One particular dive I love but have to be cautious about is the dive bluffs kids use. You can find watches, shoes, sometimes swim suits LOL. I have found wallets and sunglasses you name it.

For those who want to dive with a mission lakes offer a unique opportunity in that you can find trash all over the bottom and sometimes even more interesting finds. I found a party raft that holds 8 people once.

You can also swim through old trees that once were part of a forest and imagine being a bird as you glide through them.

There are some important factors to consider though and one is visibility. So knowing where you are diving is important because you can easily find yourself under the bottom of an old ledge somewhere and with low vis you may have to work your way out. Youll want to be sure to carry with you a flashlight as it can silt out quickly.

Be weary too that in fresh water its often more confined space wise so boat traffic can be very busy. Practice using a SMB with a real for ascent due to the high boat traffic as well and if you plan to do deep dives measure out 15 feet and mark it so you know from your SMB to do safety stops and youll have a reference to hang at.

Have fun most of all and enjoy it!

 

[Horwin]

Diving freshwater in my area is sometimes better than the ocean. The water is usually just as clear. I use less lead, and the water is clean enough that I dont have to rinse my gear. I noticed that the dive flag just attracts idiots so I dive without one in Maine. I love looking for old bottles and seeing huge sunken trees. I always wear diving earplugs in freshwater to guard against ear infections.

I also never have to worry about tides or currrents.

 

[kurtisenbecker]

Thanks to everyone for the advice. I can see now that I should have offered more information about the dive. It is in Toronto, Muskoka lake region, so there is a current (not too strong). I will be diving to a maximum of 40 feet, I will have a flag mounted to a float attached to an anchor ( I will be in one small area doing repairs to a heating system), my back up is a seasoned snorkeler only, there will be boat traffic I am sure but I will be pretty close to the dock. If everything goes well and I am finished quickly I am considering doing a little bit of a bottom search with a metal detector. Just snorkeling two years ago I found a vintage dive mask, so I am curious to see what else I can find.

---------- Post added July 31st, 2015 at 09:26 PM ----------

Oh ya, there are no gators in this region of Canada, so I am good in that regard (thanks Texasguy!). The lake sits at about 830 feet above sea level so I don't think that it will make much of a difference in my calculations especially since I will be between 30-40 feet max. I will have my flashlight with me since I already know that the bottom is quite silty. I think that once I am finished with the heating system I will attach the SMB to my BCD when I am searching the bottom (if that happens). The other thing that I thought of was the possibility of fishing line, maybe I should pack my knife...