Swimming at Anchor with Generator Running

[Mikwallace]

Ok, I’ve searched the topic above with no hits. The cruiser lifestyle is new to us and we’ll do the Survey/Sea trial next week on a 1998 405 Aft Cabin; 7.4 Horizon engines; 10 kw Kohler Generator. I’ve owned smaller boats most of my life, but none with onboard generator. I’ve also read hours and hours on this forum about the various systems. I feel I have avg/above avg mechanical knowledge and comprehend what I’ve read. I’ve also read many threads on this forum about the electrical systems and the newer ABYC/NEC codes and their issues with older boat electrical systems. I’m extremely anxious to get going with our new-to-us boat and all it has to offer over our previous boating experiences.

Other than the water sports (skiing, knee board, wakeboard), One of the experiences we really enjoyed was to drop the anchor, open the ice chest, bring out the snacks, crank up the tunes (not so loud to annoy nearby boaters), and swim/relax in the water. Since at our age we have concluded, that water sports are a thing of the past and leave those activities to the kids and grands.

So here’s the question. What’s the best policy for swimming while at anchor with the generator running?

I’ve seen boaters doing this in fresh and saltwater, but the thought really never crossed my mind. I completely understand the “No Swimming Allowed” in marinas.

What are your thoughts?
What’s your policy as the Captain?
Where does the Genny exhaust come out on the 405/406 Aft Cabin?
Is there an electrical hazard similar to the swimming in the marina issue?

There’s obviously a load of knowledge on this forum and I’m soaking it all in! Trying to stay ahead of the “Learning Curve”!

EDIT: And then this popped up in a Google Search: https://newcontent.westmarine.com/conte ... lar_86.pdf

And another: https://uscgboating.org/library/boating ... _rev_a.pdf

[Grafunkus]

Great question. I have no response as we tend to run the generator only in the morning and at dinner time. We do know a couple of people who run their generators all the time.

[Midnightsun]

My biggest concern with a gas generator is CO poisoning. At anchor it would be natural for the winds to have a station wagon effect around the stern where CO could accumulate. I would proceed with caution when people are swimming. As for stray electrical currents I do not think an on board generator is an issue for stray currents as I have not seen warnings or anything of the like in all my years of boating.

[bud37]

Those search results are good reads, especially the one concentrating on the CO issues and some accompanying stories to support the article......good stuff....there is by the way much more and the more you read the more you will be armed and aware at anchor.

So on the the electrical side, on board generators run at anchor will have any produced power run back to the generator.....but there can be a problem if you have a leaky appliance on board that leaks to the bonding system......it could under certain circumstances energize a thru hull, prop shaft etc....anything metal bonded to the system.....now if these were to be touched a swimmer could be paralyzed and be in trouble even though you are at anchor, now in salt water this is far less of a danger than in fresh water, but nevertheless awareness to these things is important in how you go forward running , maintaining and enjoying your boat.

FYI...poorly wired cheap inverters can create the same sort of issues.

It is nice to see you are taking the time to arm yourself with this info....good luck with your boat...

[km1125]

If the onboard generator or inverter is correctly installed, it will have a grounding system similar to a house. You could never actually energize a thru-hull or prop shaft, as that would be a direct short back to the grounding system.

The biggest risk is if you used an extension cord and ran it AWAY from the boat, or there was a risk that the cord end would end up in the water. THEN you'd have a current path from that extension cord back to the grounding system on the boat, through the water. That kind of thing would be dangerous for folks in the surrounding water.

I know a few folks who will run the generator while on the hook, usually so they can keep the air conditioning running. Depending on where the exhaust for the generator was, I may or may not be concerned. If it exited the stern then I'd probably shut it down while people were swimming or sitting on the swim platform. If it exited amidships I probably wouldn't shut it down.

[Viper]

Personally I'm not in the water while the genny is running, and anyone we tie off with are all on the same page that nobody runs the genny while people are in the water. We can't assume that people doing their own work know what they're doing especially when it comes to electrical wiring.

[g36]

Right or wrong we swim in the water or I should say float around. I don't run mine during the day generally either but usually aomebody in the raft up is. I try and give some distance to them more for the fumes and noise than anything else. Most of friends have cruisers which most exhaust with theirs exits the transom.

[bud37]

Source of the post You could never actually energize a thru-hull or prop shaft, as that would be a direct short back to the grounding system.

Unfortunately you can if the bonding system happens to be broken in the right place.....like I said in certain circumstances.....also consider if you are powering up a neighbouring rafted boat and they have leakage.......not worth it.....just shut it down while swimming like viper and his mates do. Never ASSUME.

[waybomb]

If you are swimming, probably not a lot of wave action, meaning light wind. CO is very slightly lighter than air, but not much.
Turn off the genny while in the water.