Oil slick in a storm to calm swell

[Bowdrie]

Originally Posted by SeanPatrick

Tell me about it. Unfortunately, mercury is not as easy to get as it used to be ... now that we know how dangerous it can be. I've been trying to convince a friend of mine to part with a small jar of the stuff, but he won't sell it. (Which is a shame, because he isn't using it for anything.)

Haha, you're so right, I said that in a jesting way.
Yeah, it's one of those products that were once common off-the-shelf items, anyone could order a flask of it.
Many years ago, and long since gone, I had a pound, (about an aspirin size bottle,) of triple-distilled dental grade mercury.
When the British were surveying India, the teams carried flasks of mercury up to the tops of their survey platforms to pour into a tray for use as an artificial horizon for their sextants.

[Woody]

There are quite a few scientific papers written on this topic and countless mariners stretching back thousands of years have found it useful enough to pass on into tradition. Whether or not you might consider it useful is up to you, and based on the situation you find yourself in.



https://en.wikipedia.org/wiki/Storm_oil

[maury]

Besides informative this has turned into a very interesting discussion.

So I am getting the gist of caution on a low deck boat and the nature of how to do it if I ever choose to which I probably won’t for fear of slippery decks. I truly appreciate all the insights. Thank you all.

[JBP]

Originally Posted by SeanPatrick

Bro...

If this technique works for an artificial horizon, I'll be forever in your debt. But as for whether or not I'd trust it as a method for saving my boat, well ...

When I was a kid and my parents were studying celestial navigation they did indeed use an artificial horizon made with a 5 gallon bucket filled mostly with water and some used engine oil on top. This wasn't for the boat but so that they could practice inland at home.

[Calif.Ted]

When I recall the last time I got caught in a gale I don't believe anything less than a leaky supertanker would have been effective. I've spent the last 10 years trying to forget about it. The size of the waves and the blowing spume, you'd end up wearing your oil. I'm gonna stick with running downwind under bare poles screaming like a Girl Scout being chased by the Cookie Monster.

[Cari Laut]

While oils were previously used with sea anchors, in 1988, Annex V of MARPOL made it illegal to dump cooking oil anywhere at sea.

[Woody]

For those interested, I recommend reading the article that Gord linked to



[2] “The Use of Oil in Storms at Sea” ~ by A. B. Wyckoff (1886)
➥ https://www.jstor.org/stable/983222


Wyckoff reviewed 115 accounts of using oil in storms and found that the practice was only unsuccessful 4 times (29:1)




Some excerpts:


Captain E.L. Arey of the schooner Jennie A. Cheney writes:

” I used oil with very satisfactory results during the late severe hurricane of the 25th of August, in latitude 31 N., longitude 790 W. The wind having carried away the mainsail, I bent a storm trysail, and continued under that sail until it also blew away. During the time, the vessel was shipping large quantities of water, the sea being very irregular, nearly every one breaking. After the sails were blown away, finding it necessary to do something to save the ship and crew, I took a small canvas bag and turned about five gallons of linseed oil into it, and hung it over the star- board quarter. The wash of the sea caused a little of the oil to leak out, and smoothed the surface, so that for ten hours no water broke aboard. I consider that the oil used, during the last and heaviest part of the hurricane, saved vessel and crew.”


and


The chief officer of the S. S. Diamond, wrecked off the Island of Anholt, describes their escape from the wreck. He provided each boat with a five-gallon can of oil, and stationed a man to pour it gradually over the stern. Immediately the sea, in the wake of the boats, became perfectly smooth, and they passed right through the boiling surf, and reached the land in safety, without shipping a sea. None of the men in the boats believed,
when they left the ship, that all would reach the shore alive; and the people on land watched their approach in wonder, deeming it impossible for even the life-boat to live in such awful breakers. (The chief officer evidently means, that the sea ceased to break in the wake of the boats; not that it became perfectly level.)

[pbmaise]

Originally Posted by Cari Laut

While oils were previously used with sea anchors, in 1988, Annex V of MARPOL made it illegal to dump cooking oil anywhere at sea.

Oh dear. I used canola oil to lubricate the head pump. Worked great and one bottle lasted many years in the tropical heat without going rancid. Kind of made me wonder if it was really good to ingest.

[peter loveridge]

In april 1971 I was taking my 24foot sailboat from Burnham on Crouch to Southampton. Weather forecasting wasn't overly good in those days and VHF for small boats hadn't been invented. I was about10 miles east of the Solent and it started to blow and the tide turned adverse. Couldn't make it to windward, started to run downwind under a small jib, hoping to enter one of the harbours downwind. Only harbour I could get to was Shoreham. Arrived at dead low water. There is only 12 feet at LW springs in the entrance. I was towing a dinghy. Breaking seas and long streaks from the wave tops. I had a metal one gallon can of engine oil on board. I mad a small hole in it,fastened a 60 foot warp to it and about a quarter of a mile from the entrance dropped it astern. It worked and didn't swamp my dinghy and I lived to tell this tale. The lockmaster had seen me coming and opened the gates for me, just as well as I thought the engine was out.Miraculously, inside the lock. in the clam water it deigned to run again

[Morris Wilson]

Oil being a different viscosity than water, ripples at a different frequency. Very good at changing the initial surface ripples but won't stop the big ones that hav been building for a thousand miles. Still I would try it any way if there was an emergency.

[Morris Wilson]

Your oil slick might save someone else.

[OS2Dude]

Originally Posted by Fuss

Speaking of caring...Not the 4000 cruise ship tourists, dumping s##t everywhere that for sure!!...

Yeah, because all those freighters hauling all the cheap crap you are buying all hold it until they get to shore. Oh, and let's not forget the waterborne lifeforms that wait until the dark of night to sneak ashore to use the bathrooms. And you thought those turtles were coming ashore to lay eggs...

[Morris Wilson]

OS@Dude You got it right. We're all guilty.

[maury]

Yes the idea of having as a method in an emergency was my thought in asking about it. I was actually considering buying a cheap food grade oil to carry with flares and emergency supplies. As for applicable regs discussed they say “used” food oils.

[Epikur]

Originally Posted by Jim Cate

FWIW: From memory, the method was indeed only used when hove to and not making headway... where the natural slick from the upwelling of water from under the keel was being maintained upwind of the boat. The oil was usually contained in a closely woven hemp bag, or a tin can, often with deliberate small holes to allow easier egress for the oil. The oil used was simply known as "fish oil", source unknown to me. And the quantities used were not spoonfuls, but more like liters/day.

It was a common means of diminishing the effects of breaking seas. I believe my knowledge of it most likely came from old editions of Adlard Coles "Heavy weather Sailing" tomes.

Jim

I see two aspects:
1) oil indeed flattens waves but I assume the effect on a breaker is minimal

2) As Jim Cate explains, to apply the oil you are in hove-to and, if it is done right, you are slipping sideways only. The oil is „moving to windward“, or rather you are moving to leeward and dragging the oil bag behind you. The slik, or turbulence induced by your keel, you drag behind you has the effect that the wave will just not break on your boat. That’s described by the Pardeeys in „Storm Tactics“. „Waves are breaking in front and behind the boat in hove-to, but not onto the boat“.
The oil is merely the indicator that your hove-to attitude is right.

What are your opinions?