My flats boat sits on top of a jet dock. Boat is totally out of the water and is connected to a Guest Marine onboard battery charger that charges both my starting battery as well as my trolling motor battery. Sunday afternoon I was in the creek with my kids playing. I was standing on a paddle board with wet hands when I reached over and touched the prop. I noticed a very slight shock. At first I thought it was a slight sting from a jellyfish but then realized I was actually being shocked. I leave the battery switch off when I’m not using the boat and I’m quite confused on where the stray current could be coming from. I seriously doubt this is normal. Any ideas as to where to start?
Curious to what you will find??
Sounds like you have AC to the dock. Turn off breaker feeding dock at source and see if that helps.
NN
Get out of the water and don’t touch the prop! Something is wrong. Maybe reversed polarity somewhere or a bad ground. Not sure, but it is NOT normal 
[:0]
Capt. Larry Teuton
Swamp Worshiper
Get a groung fault breaker or receptacle on that circuit ASAP. They should trip out any time there is a problem.
AC and water don’t mix! Check it out quick. Like spoon master said install a groundfault ASAP!!
I plan to install a GFCI outlet tonight. I had removed the original GFCI because it kept going bad due to the elements. It is in a weather proof box with weatherproof cover and I even have a bucket over the top of it to keep it dry but they still only seem to last a year or so then I have to replace. I tested the circuit last night and it shows open ground. Guess ground wire from house to dock must have come loose somewhere along the line. If GFCI does not fix, then might have to run new wire. Still not certain all of this is coming from the AC dock power. Shock was so light even with wet hands and feet that I have to think it may be a 12v bleed over from somewhere. I checked and polarity shows correct on everything hooked to battery’s and switch and like I said battery switch was turned off when I got shocked. If any accessory such as bilge, radio etc was reversed then it should be popping the fuse associated with it so II am still baffled.
You need to get this fixed asap.
If it get worse could be more than
a tingle to someone.
GFI or new wire if that doesn’t
fix it.
Contender1 ; Having been an electrician for toooo many years , and
knowing the dangers of electrical current, my advise is to call in
an electrician, he/she will have the test equip to pin point your
problem. After repair, I would ask electrician to coat all terminals
concerned with liquid tape; it will extend the life of equipment
for a long time against the elements.
Please don’t allow anyone to come into dock area until fixed!!!
SAFETY FIRST!!! You can fix the problem, but can’t undo
an accident after it happens.
[http://www.militaryappreciationday.org
When you see “Old Glory” waving in the breeze, know that it is the dying breaths of our fallen hero’s that makes it wave.
author unknown
GUYS, DONT PANIC YET…
IT COULD ALSO EASILY BE A SIMPLE 12 VOLT D/C SHORT AS WELL.
START BY UNPLUGGING THE BATTERY CHARGER FIRST THEN CHECKING FOR A SHORT.
Wire from house to dock was up in age so I went ahead and pulled new wire through conduit. Installed new GFCI outlet as I knew this really needed to be done anyhow. Tested outlet and no more open ground fault. Plugged battery charger back up and no issues with GFCI tripping. As Chris said above i believe I actaully have a 12v dc short somewhere. Not sure where or how this is possible because none of the accessories are failing or blowing fuses but I will now have to start running wires down in the boat. At least I can sleep better now knowing the 115 V is not an issue for sure and that it is properly wired up and has GFCI.
Do you happen to have another dock in close proximity to yours? One that has shore power ran to it. If you do, and it is close enough, that could also cause this.
Hopefully you have solved your problem tho.
NN
A GFI won’t work unless an active ground is on the curcuit!
Agree with Gail Winds! Safety First! I work for a Power Company and have seen some strange things with electricity, shore power, docks, etc.
Don’t take a chance. PM me if you are unable to determine what’s causing the problem. I will come and help you free of charge (maybe you can point me to a fishing spot or two)!
I believe issue has been resolved. No more open ground on the circuit and GFCI has been replaced. Feeling comfortable that I have the AC current issue fixed I touched motor with wet hands last night and no tingle. Still not 100% sure what was causing it before but can’t help but think it was something DC related. I am going to continue to check on a regular basis but I belive it is ok now.
wet hands wont do it
you need wet hands and wet feet
current needs a path to ground
use a cheap electrical tester instead of your body
put one lead on the motor, and the other in the water and read the voltage
the start unplugging stuff. I would start witht eh battery charger
XXX 100 on what chris v said , take nothing for granted!!!
Take bkdraper62 up on his offer if he has proper test equip… you may still have ,IMHO, an accident just waiting for the right conditions to align them selves and the consequences could be fatal. Water/wet conditions DO NOT MIX.[:0][:0]
[http://www.militaryappreciationday.org
When you see “Old Glory” waving in the breeze, know that it is the dying breaths of our fallen hero’s that makes it wave.
author unknown
I’m with Chris and Gail Wins. Get a professional And never test for electrical problems with your hands!
Capt. Larry Teuton
Swamp Worshiper
Well I guess I should have been a little more clear, I tested with my electrical meter on both DC and AC before touching motor. Believe it or not I am not quite as dumb as I sound. #128516; I was grounded back to the boat battery and no significant voltage showed. . I did not try it with a test lead in the salt water, but would expect the same results as grounding back to battery. If there is no voltage showing on the motor I don’t know how I could run any more tests.
The negative side of the crank battery is connected to the engine block (includes prop) and sometimes referenced back to the shore power ground if you have an onboard charger plugged in (3-prong male connector). These circumstances could place the prop at ground (earth) potential. If by some chance there is stray AC voltage in the water, then touching the prop completes the circuit and you will receive a shock. Set-up your voltmeter to read AC volts. Attach one lead to your prop and the throw the othe lead in the water. If you read anythng greater than a volt or two, you have a problem.
Stray voltage can come from many places, including your neighbor’s dock, water heaters, underground wires, etc.
contender1 you’re not sounding dumb; actually sounds intelligent to know that you have a unknown problem. IMO you might still have the problem, as you stated your test assumed reading to ground of battery
would be same as reading to the salt water , it won’t , especially if
current is coming from another source than battery!!! With these type
of problems… ASSUME NOTHING. I’LL say no more.
[http://www.militaryappreciationday.org
When you see “Old Glory” waving in the breeze, know that it is the dying breaths of our fallen hero’s that makes it wave.
author unknown