I have a 2016 Nitro Z21. Bought the boat used and don't think it's seen salt water. Maybe some brackish but don't think full salt.have had the boat a few weeks and noticed today some white powdery substance on the Atlas jackplate and on some screw on my brand new Ultrex trolling motor.
Can someone please point me in the right direction.. today I was on Texoma

I'm sure there is a technical process for this, but not that smart....

screw heads - pretty common if you're on lakes with high mineral content, which texoma is really high.
Jack Plate - looks like an anode....also looks like it might have spent some time in a slip. I've seen this on my anodes, just powerwash off. Will see the powdering on bolts on the transom after a season or two, I just bought an Ultrex in May, haven't noticed it, but now have to go look.

I think as long as it isn't "pitting"? the metal you're okay...but I'm not a chemist or metal specialist.

Texoma has really high mineral content almost like salt water. That's probably what caused it.

Ok. Next time i.go to Ray Roberts I'll look. And. Y the way the Ultrex is worth the money. Lol

it looks like you have some electroalisis going on and if youput your boat in texoma pk or other brazos chain lakes they are very salty.

Most likely electrolysis (might be minerals if those lakes really do that, never heard of it though), do you in anyway have the trolling motor ground wires tied/attached to the cranking battery's ground? Look real hard, because it will eat your boat up if you do.

Trolling motors batteries are not hooked up to cranking batteries. I took all batteries out when got the boat and cleaned the bilge.

Agree. You have a big ground problem somewhere. It will cover everything metal that is in the water eventually; from the motor prop and jack plate to the trolling motor.

Fishfinders, multi battery selecter, etc. anything that has somehow been attached to the crankers & troller battery. You want to find the issue before you get a serious problem.

I'm pretty sure the 3 lowrance hds gen 3s are all run to the cranking battery. I thought that was weird cause with master power switch off they all still have power. Would that have something to do with it maybe?

I don't remember seeing this kind of powder on my jackplate after going to Ray Roberts a few times. This is the 1st time on Texoma tho

Another thing about the fishfinder and trolling motor. If I put a skimmer HDI on the trolling motor. And ha r it connected to the bow graph that's con eyed to the cranking battery. What about that.

Electrolysis, figure out the source or it will cause your severe electrical gremlins in the future.

I have a Z19 and the grounding wire broke and before i fixed it i started to get the same thing.
Look at the small wire that attaches to the bolt on the lower unit where your motor mate sets. It's on the passenger side and hard to see but if its broken you will not ground.

Yes . I do have a broken one. I have been wondering what it was..Have a link where to buy another...