Brackish water Marina?

[Mach_cat]

Hi
Possibly looking at mooring on the Dawamish River in Seattle. This is a brackish water Marina with the outlet near by to Puget sound.
Is there any issues with brackish water for corrosion? Bottom paint?
Thanks Ed

 

[Giggitoni]

We've been in brackish water for nearly nine years (Napa River confluence with Carquinez Strait, San Francisco Bay Area). I consider it a plus as opposed to pure ocean water closer to San Francisco. We have reduced marine growth between hull cleanings as well as reduced electrolysis.

Consult with a marine corrosion control expert as to what type of "zincs" to use in your area. Some say aluminum are better than zinc in brackish conditions.

 

[bshanafelt]

you should be able to get 3 years between bottom jobs in that location.
Probably good to check you zincs on a regular basis.

 

[Phil Fill]

We are moored in the Everest marine because it's brackish water. Brackish water is fresh water floating on top of salt water because fresh is lighter. Therefore, the boat could be floating in freshwater. Bottom paint and zincs last 3+ years. In the spring I have a diver check the zincs and clean the prop and through hulls.

 

[sbu22]

I'm docked in Lake Pontchartrain (New Orleans) which is actually an estuary, not a lake. We typically see single digit salinity, measured in parts per thousand (ppt). Today it's 0.8 ppt. Open ocean salinity generally runs 35-37 ppt, I understand.

My boat sometimes will spend several months in coastal marinas on the Gulf - the difference in corrosion rate (greater in the Gulf) is visible to my eye in that time period. Not just in below waterline components, but topside where exposed to spray. Everyone on the Lake that I know has stayed with zinc anodes.

In my experience, the effects of brackish water versus seawater is all beneficial with the former. Anodes last longer, less visible corrosion, bottom job intervals about the same. Using Trinidad bottom paint. I don't see any downsides. YMMV.

 

[HopCar]

Some bottom paints don't work well in brackish water. I've had very good results with an older version of Interlux Micron Optima. I haven't tried the new version but it is said to work in all types of water.

 

[Gulf Comanche]

Brackish or fresher water means no barnacles, only green scuz that'll power wash off. Need to get mine hauled for that soon, been a couple 2-3 years since last haul.

 

[CPseudonym]

...

 

[rwidman]

Brackish or fresher water means no barnacles, ...........

That is not my experience. Barnacle growth depends on lots of things.


As for bottom paint, the major paint manufacturers have selection guides on their websites. Talking to other boaters in the marina and divers who work the marina will also help in your selection of paint.