I want to dive under the boat in the calm of the marina to clean the prop and bottom, but I am concerned about stray current in the water of the marina. Does anybody know of a simple test to check for stray current? Chuck Kent Island, MD
Stray Marina Electricity
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Chuck , just put the leads of a multimeter
into the water, one on each side of the boat and take a reading. But first go out in your front tard and stick the leads into wet ground and take a reading. The voltage should be very close to ZERO. Edit to add: check both AC and DC
into the water, one on each side of the boat and take a reading. But first go out in your front tard and stick the leads into wet ground and take a reading. The voltage should be very close to ZERO. Edit to add: check both AC and DC
Divers
I've read the accounts of the risks of stray current in marinas. However, in our marina (and no doubt most marinas of the world) divers go under virtually all the boats every month or two to scrub the bottoms. I can't imagine they would do that if the risk were unusually high.
I've read the accounts of the risks of stray current in marinas. However, in our marina (and no doubt most marinas of the world) divers go under virtually all the boats every month or two to scrub the bottoms. I can't imagine they would do that if the risk were unusually high.
Don't jump in if you use Ross's method
The potential on either side of the boat will be the same or close to it. It's like putting both leads of the meter on one wire. You have to put one lead to ground and then the other in the water. You won't ge fried when in the water unless you touch something that is grounded. Like the prop, shaft, dock ladder and the list goes on. Fair Winds and good luck Cap'n Dave
The potential on either side of the boat will be the same or close to it. It's like putting both leads of the meter on one wire. You have to put one lead to ground and then the other in the water. You won't ge fried when in the water unless you touch something that is grounded. Like the prop, shaft, dock ladder and the list goes on. Fair Winds and good luck Cap'n Dave
Several things to check.
You could get a reverse polarity tester and ensure that your boat and all electrical boxes to the left and to the right of your boat have the correct polarity. If you dont have a polarity tester, measure with a volt meter - line to ground, and neutral to ground 120VAC and 0-2 VAC respectively. Neutral to ground voltages are not always zero - that's normal. Second, make sure all the boats to the left and right of you are using approved Marine shore power extension cords - you know the yellow ones with molded connectors at each end. Better yet - unplug them if you can! You should ask the marina if they test their GFI. Heres a real good test to see if the GFI at the marina is working OK. Insert an 18K Ohm - 1Watt resistor between the hot wire and ground. If the GFI is working, the 18K from line to ground should make it trip. Capn Dave - You dont need to be touching metal to get fried - you only have to be in the path of the current. If current is flowing through the water and you are in it's path, lets just say you'll stop paddling. Talk to your marina - maybe they will be the best help.
You could get a reverse polarity tester and ensure that your boat and all electrical boxes to the left and to the right of your boat have the correct polarity. If you dont have a polarity tester, measure with a volt meter - line to ground, and neutral to ground 120VAC and 0-2 VAC respectively. Neutral to ground voltages are not always zero - that's normal. Second, make sure all the boats to the left and right of you are using approved Marine shore power extension cords - you know the yellow ones with molded connectors at each end. Better yet - unplug them if you can! You should ask the marina if they test their GFI. Heres a real good test to see if the GFI at the marina is working OK. Insert an 18K Ohm - 1Watt resistor between the hot wire and ground. If the GFI is working, the 18K from line to ground should make it trip. Capn Dave - You dont need to be touching metal to get fried - you only have to be in the path of the current. If current is flowing through the water and you are in it's path, lets just say you'll stop paddling. Talk to your marina - maybe they will be the best help.
Russian Roulette
Given the crappy conditions at most marinas, getting in the water there is similar to Russian Roulette. A few years ago, I guy at a local marina climbed down his boarding ladder into the water in his slip to clean his prop. Stray current in the water seems to have caused him to have a "minor" heart attack. He doesn't do this anymore. Nor does anyone else. If you are considering this action, talk to your marina manager first and see what he says about the dangers, or lack thereof. A lot of marinas will not allow you into the water there because they know the liability issues are pretty high.
Given the crappy conditions at most marinas, getting in the water there is similar to Russian Roulette. A few years ago, I guy at a local marina climbed down his boarding ladder into the water in his slip to clean his prop. Stray current in the water seems to have caused him to have a "minor" heart attack. He doesn't do this anymore. Nor does anyone else. If you are considering this action, talk to your marina manager first and see what he says about the dangers, or lack thereof. A lot of marinas will not allow you into the water there because they know the liability issues are pretty high.
Shut the power
Just unplug the boats nearby your boat,I agree with Gary divers are always under boats doing work and I would be more concerned with the water quality in a marina. Oh and BTW most marina's 30 or 50 amp outlets are not GFI protected
Just unplug the boats nearby your boat,I agree with Gary divers are always under boats doing work and I would be more concerned with the water quality in a marina. Oh and BTW most marina's 30 or 50 amp outlets are not GFI protected
Anchor out
Go find a nice and quiet cove and drop anchor. Have a lookout with cell phone or VHF watching over you. No boat or shore power around so you'll be safe. Just don't dig the underwater cable.
Go find a nice and quiet cove and drop anchor. Have a lookout with cell phone or VHF watching over you. No boat or shore power around so you'll be safe. Just don't dig the underwater cable.
Unplugging other people's boats
may not be the right thing to do. It's like halyards slapping: The Romantic Sound Of Clanging Halyards Sunday, November 28, 2004 By Capt. Alan Hugenot Have you ever been woken up at night while sleeping in a marina because the neighboring sailboat’s halyards were banging against the mast in the wind? If you have ever tried to sleep through this constant noise, which is like someone continuously knocking on your door, then you know the dilemma which this causes for any poor sailor trying to sleep nearby. Of course, the skipper of the offending boat is not there to hear the incessant slap, slap, slap, and he probably wants to keep those halyards ready to hoist sail as soon as he comes aboard, totally unaware that by doing so he is creating a nerve-racking noise machine. So what can you do? You can’t sleep and you are conflicted about what action to take. You know that if you go aboard his boat and swing the halyards outboard around the spreader before making them fast again that the incessant slap will stop. And, you wonder why the inconsiderate skipper did not do that before he stowed his boat. Maybe you also know that he only comes down to the marina once a month or even less to check his boat. You know he is totally unaware that you have to listen to his halyards going slap, clang, slap, clang every night. On the other hand if you go aboard his boat to fix the problem, it will actually be trespassing - not quite breaking and entering - but trespassing none the less. When he comes back to the boat, he may even get angry at the “prankster” who tangled his halyards around the spreaders, thinking “who would do such a thing, just to confound him.” He, of course, never realizing the true reason unless you tell him. Yet, from a different perspective you might only be a “good Samaritan.” For instance, if the halyard were loose and about to carry away through the top of the mast, then that same skipper would want you to quickly go aboard his boat (even though he had not given you permission) and “properly” secure it. That simple act of neighborly seamanship would save him the grief of having to go aloft to re-thread the halyard through the top of the mast. So wouldn’t it be the same thing here? His halyard is clearly wearing itself out beating against the mast, and if you will just “properly” stow it for him, then it will not wear out as quickly. Also your nerves won’t wear out as quickly either. This is no small problem. I have lived aboard for several years, in both Seattle, Wash. and San Francisco, and have also spent a night or two in nearly every marina from San Diego to Seward, Alaska. In every one there are these slapping halyards. At first you might think that a polite word to the offending skipper would solve the problem. But, a couple of times when I asked the owner of an offending boat if they could take a moment before going ashore to quiet their halyards by rigging them away from the masts, they became defensive. They acted like I was being rude for butting into their business, criticizing their seamanship. They arrogantly pointed out that they knew what they were doing, had studied proper halyard techniques, and had graduated from ASA or US Sailing. They were not going to quiet their halyards by rigging them outboard. Besides who was I to tell them anything. In one case the offending skipper said that “If they found their halyards any different than how they chose to leave them” then they would blame me for trespassing on their boat, and would report it to the marina manager. After this encounter, I could not stop the noise from his boat, and wished I had never spoken to him about it. I knew that if I had never brought it up, I could have quieted his halyards and he would not know who “fouled” his lines. Instead, I changed marinas and learned the lesson that my safest bet was to quiet all offending halyards myself, and do so without telling the owner that I was the culprit. This “don’t ask, don’t tell” policy allowed me to sleep, and several weeks later when the offending skipper turned up to sail his boat I was not there to hear his wrath about “Whoever fouled his halyards was going to catch hell.” I guess it comes down to who is more inconsiderate: Me for trespassing on his boat, or him for leaving the noisy halyard slapping against the mast. It is such a simple thing to just tie the halyards off on the shrouds, or swinging them around the spreaders. Maybe 60 seconds to quiet every halyard on the boat. Another, idea is to use a shock cord to pull them over toward the shrouds and away from the mast, and there are dozens of other ways to stop the slap, slap, slap. Of course no way am I advocating that you climb on someone’s boat and adjust their halyards. Trespassing is something I would never encourage you to do. Several times in marina parking lots I have heard novice boaters saying “Wow, listen to the clanging of the all the sailboats in the wind. Isn’t it romantic.” So maybe it is a matter of perspective, or rather ignorance of the harm that may be caused by what may be romantic to one person and pollution to another, depending upon perspective. It baffles me to no end why sailing instructors don’t teach this simple courtesy to their students. It seems that simple courtesy should always be part of every lesson for novice sailors. We live pretty close together on the water, which means we need to cultivate proper manners and respect for our fellow boaters. Learning how to rig our boat so that it does not create undue noise pollution should be part of every sailing lesson. Actually, in California the boating laws are beginning to take notice of noise pollution. Beginning in the fall of 2004 agencies will begin to enforce a new law that makes it illegal to have a power boat that is too noisy. Maybe this idea that noise pollution on the water is a crime can be stretched to include sailboats that are too noisy. Clang, slap, clang - but it’s so romantic. Yea, right.
may not be the right thing to do. It's like halyards slapping: The Romantic Sound Of Clanging Halyards Sunday, November 28, 2004 By Capt. Alan Hugenot Have you ever been woken up at night while sleeping in a marina because the neighboring sailboat’s halyards were banging against the mast in the wind? If you have ever tried to sleep through this constant noise, which is like someone continuously knocking on your door, then you know the dilemma which this causes for any poor sailor trying to sleep nearby. Of course, the skipper of the offending boat is not there to hear the incessant slap, slap, slap, and he probably wants to keep those halyards ready to hoist sail as soon as he comes aboard, totally unaware that by doing so he is creating a nerve-racking noise machine. So what can you do? You can’t sleep and you are conflicted about what action to take. You know that if you go aboard his boat and swing the halyards outboard around the spreader before making them fast again that the incessant slap will stop. And, you wonder why the inconsiderate skipper did not do that before he stowed his boat. Maybe you also know that he only comes down to the marina once a month or even less to check his boat. You know he is totally unaware that you have to listen to his halyards going slap, clang, slap, clang every night. On the other hand if you go aboard his boat to fix the problem, it will actually be trespassing - not quite breaking and entering - but trespassing none the less. When he comes back to the boat, he may even get angry at the “prankster” who tangled his halyards around the spreaders, thinking “who would do such a thing, just to confound him.” He, of course, never realizing the true reason unless you tell him. Yet, from a different perspective you might only be a “good Samaritan.” For instance, if the halyard were loose and about to carry away through the top of the mast, then that same skipper would want you to quickly go aboard his boat (even though he had not given you permission) and “properly” secure it. That simple act of neighborly seamanship would save him the grief of having to go aloft to re-thread the halyard through the top of the mast. So wouldn’t it be the same thing here? His halyard is clearly wearing itself out beating against the mast, and if you will just “properly” stow it for him, then it will not wear out as quickly. Also your nerves won’t wear out as quickly either. This is no small problem. I have lived aboard for several years, in both Seattle, Wash. and San Francisco, and have also spent a night or two in nearly every marina from San Diego to Seward, Alaska. In every one there are these slapping halyards. At first you might think that a polite word to the offending skipper would solve the problem. But, a couple of times when I asked the owner of an offending boat if they could take a moment before going ashore to quiet their halyards by rigging them away from the masts, they became defensive. They acted like I was being rude for butting into their business, criticizing their seamanship. They arrogantly pointed out that they knew what they were doing, had studied proper halyard techniques, and had graduated from ASA or US Sailing. They were not going to quiet their halyards by rigging them outboard. Besides who was I to tell them anything. In one case the offending skipper said that “If they found their halyards any different than how they chose to leave them” then they would blame me for trespassing on their boat, and would report it to the marina manager. After this encounter, I could not stop the noise from his boat, and wished I had never spoken to him about it. I knew that if I had never brought it up, I could have quieted his halyards and he would not know who “fouled” his lines. Instead, I changed marinas and learned the lesson that my safest bet was to quiet all offending halyards myself, and do so without telling the owner that I was the culprit. This “don’t ask, don’t tell” policy allowed me to sleep, and several weeks later when the offending skipper turned up to sail his boat I was not there to hear his wrath about “Whoever fouled his halyards was going to catch hell.” I guess it comes down to who is more inconsiderate: Me for trespassing on his boat, or him for leaving the noisy halyard slapping against the mast. It is such a simple thing to just tie the halyards off on the shrouds, or swinging them around the spreaders. Maybe 60 seconds to quiet every halyard on the boat. Another, idea is to use a shock cord to pull them over toward the shrouds and away from the mast, and there are dozens of other ways to stop the slap, slap, slap. Of course no way am I advocating that you climb on someone’s boat and adjust their halyards. Trespassing is something I would never encourage you to do. Several times in marina parking lots I have heard novice boaters saying “Wow, listen to the clanging of the all the sailboats in the wind. Isn’t it romantic.” So maybe it is a matter of perspective, or rather ignorance of the harm that may be caused by what may be romantic to one person and pollution to another, depending upon perspective. It baffles me to no end why sailing instructors don’t teach this simple courtesy to their students. It seems that simple courtesy should always be part of every lesson for novice sailors. We live pretty close together on the water, which means we need to cultivate proper manners and respect for our fellow boaters. Learning how to rig our boat so that it does not create undue noise pollution should be part of every sailing lesson. Actually, in California the boating laws are beginning to take notice of noise pollution. Beginning in the fall of 2004 agencies will begin to enforce a new law that makes it illegal to have a power boat that is too noisy. Maybe this idea that noise pollution on the water is a crime can be stretched to include sailboats that are too noisy. Clang, slap, clang - but it’s so romantic. Yea, right.
Stu, slapping halyards the same?*o
As an electrician I work in marina's all the time and do turn off the juice to work on the outlets and in the interest of saftey whether the boat owner was around or not whats the big deal? if there was a brief power outage it would be the same thing and for the record I've turned off my neighbors juice to check a friends prop next to my slip and would do it again in a split second. Of course if your neighbor is around you would ask to shut the power off. /
As an electrician I work in marina's all the time and do turn off the juice to work on the outlets and in the interest of saftey whether the boat owner was around or not whats the big deal? if there was a brief power outage it would be the same thing and for the record I've turned off my neighbors juice to check a friends prop next to my slip and would do it again in a split second. Of course if your neighbor is around you would ask to shut the power off. /
Salt Water Versus Fresh
Fresh water is more dangerous as to a stray current killing you. Salt water is a much better conductor of electrcity and quickly takes current to ground. The most dangerous is stratified water with water with less salt and more salt in layers. In this case your body provides a less resistant channel for the current. A friend of my wife had her husband drown very mysteriously while swimming near a dock in a freshwater lake. He was an excellent swimmer and just stopped swimming and sank. Classic signs of stray currents. If you search around the web there are articles. Boatus.com might be a place to start as they ran some articles a few years ago. I remember years ago swimming at a pool that had an underwater light that would shock us if we touched it...a miracle that I wasn't electrocuted. We kids discussed it among ourselves.
Fresh water is more dangerous as to a stray current killing you. Salt water is a much better conductor of electrcity and quickly takes current to ground. The most dangerous is stratified water with water with less salt and more salt in layers. In this case your body provides a less resistant channel for the current. A friend of my wife had her husband drown very mysteriously while swimming near a dock in a freshwater lake. He was an excellent swimmer and just stopped swimming and sank. Classic signs of stray currents. If you search around the web there are articles. Boatus.com might be a place to start as they ran some articles a few years ago. I remember years ago swimming at a pool that had an underwater light that would shock us if we touched it...a miracle that I wasn't electrocuted. We kids discussed it among ourselves.
Would not think the current flow of elctricity
coming from a 120V power source into a large volume of water would be of any consequence to a diver. Perhaps a 10,000 volt transmission line in a kiddie pool might be a different story.j
coming from a 120V power source into a large volume of water would be of any consequence to a diver. Perhaps a 10,000 volt transmission line in a kiddie pool might be a different story.j
Unplug it RAD!
As an electrician you know that turning off the switch only breaks one leg and it should be the hot leg. If the polarity was reversed, you would only be breaking the neutral leg - not so good since the ground fault comes from the hot leg - which is still connected through the plug. Better to unplug than to turn off!
As an electrician you know that turning off the switch only breaks one leg and it should be the hot leg. If the polarity was reversed, you would only be breaking the neutral leg - not so good since the ground fault comes from the hot leg - which is still connected through the plug. Better to unplug than to turn off!
Monty,
Great link, I have read that same link awhile back cause I'm a regular on there email list and other industry related web sites. I've seen a lot of wiring on boats and its amazing what the so called marine mechanics and boat owners do with wiring and that goes for the 12 volt and 110 volt stuff. I have a friend with a 54 Trumpy Motor yacht and it has a 32 volt DC,12 volt DC and 110/240 AC systems and what a nightmare since the boat is a 1959 and every Tom,Dick and Harry the mechanics has had there hands on it. Its been an ongoing project to sort out and label all systems.
Great link, I have read that same link awhile back cause I'm a regular on there email list and other industry related web sites. I've seen a lot of wiring on boats and its amazing what the so called marine mechanics and boat owners do with wiring and that goes for the 12 volt and 110 volt stuff. I have a friend with a 54 Trumpy Motor yacht and it has a 32 volt DC,12 volt DC and 110/240 AC systems and what a nightmare since the boat is a 1959 and every Tom,Dick and Harry the mechanics has had there hands on it. Its been an ongoing project to sort out and label all systems.
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