Potomac River Boat Owners

[PotomacBassin]

I was wondering how many of you flush your motors after every outing because of the brackish water.  Mercury (and I'm sure other manufacturers) recommend it after using it in brackish water but it just seems a little bit of overkill.  I store my boat away from my house so it's hard to do this often.

[beergogglin]

It's only brackish relatively close to the mouth at the Chesapeake right?

How far up is it still considered "brackish"?

[Sam]

I run my motor to get the gasoline out of it and to flush it out every time I take her out of the water.

 

I start the motor and remove the fuel line to the motor and let her run until she is out of gas.

 

Of course you will need a set of "ears" to do this to keep the water going into the motor.

 

Give it a shot.

[Sam]

Beer, depending on the amount of rain the brackish water in the Potomac can move up river fast.

 

Just look for the crabs.

 

Friends have caught red fish, croakers and flounder in Mattawoman Creek!

[Traveler2586]

I have seen some "False Color" satellite images of the Chesapeake Bay and Potomac River where you can actually see the salt wedge.

 

Basically a lot depends on the amount of rainfall we get up in the mountains as the salt wedge (brackish water) line moves up and down the river seasonally.

 

I believe generally speaking the southern average limit of fresh water is around Blossom Point MD and the northern limit of brackish water is somewhere around Moss Point MD, above that it's usually considered fresh water.

 

But like I said it all depends on how much rain both the Potomac River watershed and the Susquehanna River watershed receives seasonally.

 

I usually fish from Nanjemoy Creek, MD up to the Key Bridge area of D.C. and have never seen any effects to my motor to worry about flushing my engine.

[Traveler2586]

Here is some data from the NOAA Smart Buoys for the Lower Potomac at Point Lookout, and the Upper Potomac at the W.W. Bridge.  Look at the scale on the left of the graph.

 

 

 

 

 

 

From NOAA:

 

Salinity

Salinity is the concentration of salt in the water. CBIBS measures salinity in practical salinity units--PSUs. (Salinity is also available in parts per thousand--ppt.) Salinity levels are a function of the mixing of ocean waters, which contain approximately 32 ppt (parts per thousand) salinity with freshwater from the Bay’s tributaries (< 1 ppt salinity). This is reported as an hourly average. Salinity is an important factor in determining where the Bay’s plants and animals live and in some cases when the animals reproduce or migrate. In any given location, salinity can vary greatly depending upon river flow, being low during high flows and high during droughts. Most of the Bay’s living resources are adapted to these large swings in salinity, but extreme floods or droughts can lead to stressful conditions.

[PotomacBassin]

I have seen some "False Color" satellite images of the Chesapeake Bay and Potomac River where you can actually see the salt wedge.

 

Basically a lot depends on the amount of rainfall we get up in the mountains as the salt wedge (brackish water) line moves up and down the river seasonally.

 

I believe generally speaking the southern average limit of fresh water is around Blossom Point MD and the northern limit of brackish water is somewhere around Moss Point MD, above that it's usually considered fresh water.

 

But like I said it all depends on how much rain both the Potomac River watershed and the Susquehanna River watershed receives seasonally.

 

I usually fish from Nanjemoy Creek, MD up to the Key Bridge area of D.C. and have never seen any effects to my motor to worry about flushing my engine.

Thanks guys.  I'm usually from Quantico/Chicamuxen to North of that. 

[PotomacBassin]

Beer, depending on the amount of rain the brackish water in the Potomac can move up river fast.

 

Just look for the crabs.

 

Friends have caught red fish, croakers and flounder in Mattawoman Creek!

I see crab traps the whole way up to Neabsco almost every year.  Does it always mean, where there are crabs there is salt?  I wasn't sure if these were freshwater crabs or not. 

[Traveler2586]

I see crab traps the whole way up to Neabsco almost every year.  Does it always mean, where there are crabs there is salt?  I wasn't sure if these were freshwater crabs or not. 

 

They could be fish traps.

[CMG]

They're crab traps.  Last year I saw traps up to the northern part of the mouth of Occoquan.  They wouldn't be there if they weren't catching anything.  Last year I caught a blue crab at the mouth of Mattawoman.

[PotomacBassin]

They could be fish traps but I caught a crab in neabsco before and saw them in powells creek along the bank before. I guess I just always assumed they could be freshwater crabs.

[Traveler2586]

Well we know some salinity makes its way up to DC, I've caught Rocks (Striper's) at the Rte. 95 (W.W.) bridge.  But I can't say I've ever seen any effects to my engine from the salinity.  Now down in the Lower Potomac (PT. Lookout) and Solomons Island areas, Yes, I have seen engine anodes heavily affected by the salinity.

 

Maybe we have a citified marine technician on the forum that can add something here.  We know the salinity range from the charts above.