Doing a 360 degree spin to set compasses

[LoyalRoyal 1973]

I had a unique experience on a recent cruise with my sister. We went to the Viking Crown Lounge as we were leaving port in St. Thomas at sunset. We got to see everything as we left and sailed away, right at sunset, as the lights then began to come on back across the island. That experience was amazingly beautiful enough, but then we had an unexpected bonus. The captian came on the PA to tell us all that we were about to pause and do a 360 degree turn in place to set our compasses. We sailed far enough from port to get an amazing view, but were still close to shore with the lights twinkling on land. We stopped in place and the ship turned to the four points of the compass and paused at each of the four points for a couple of minutes. We got a 360 view with pauses and it was awesome. Then, we cranked up and sailed onward. The captain said they just have to do this function rarely. I wish I knew how to know what dates a cruise ship was carrying this function!!!! I would book for that experience again. It seems like a "rare in a lifetime" unexpected event on a large cruise ship. :) Anyone else ever experience such? Stories? I know they try to spin in the Alaska bays when visiting glaciers - I have experienced that, but never a complete circle with pauses like the St. Thomas night. In the glacier bays my memory was they went in, spun 180, and then went out.

[chengkp75]

I had a unique experience on a recent cruise with my sister. We went to the Viking Crown Lounge as we were leaving port in St. Thomas at sunset. We got to see everything as we left and sailed away, right at sunset, as the lights then began to come on back across the island. That experience was amazingly beautiful enough, but then we had an unexpected bonus. The captian came on the PA to tell us all that we were about to pause and do a 360 degree turn in place to set our compasses. We sailed far enough from port to get an amazing view, but were still close to shore with the lights twinkling on land. We stopped in place and the ship turned to the four points of the compass and paused at each of the four points for a couple of minutes. We got a 360 view with pauses and it was awesome. Then, we cranked up and sailed onward. The captain said they just have to do this function rarely. I wish I knew how to know what dates a cruise ship was carrying this function!!!! I would book for that experience again. It seems like a "rare in a lifetime" unexpected event on a large cruise ship. :) Anyone else ever experience such? Stories? I know they try to spin in the Alaska bays when visiting glaciers - I have experienced that, but never a complete circle with pauses like the St. Thomas night. In the glacier bays my memory was they went in, spun 180, and then went out.

 

You would never know in advance. This is an annual (maybe every two years) requirement to compare the magnetic compass reading with the gyro compass to get what is called "deviation". The magnetic compass is only used when the gyro compass fails, but swinging the compass is a hold over from the old days before gps. The Captain will choose a time and place where it is least disruptive of the ship's schedule.

[LookingForward2]

What a great experience!

and...what a great explanation

 

I know how excited I get whenever the ship does the 180 to back in or turns to leave a port - this would really be something to watch. thanks for sharing!

[Paulxyz2004]

I had a unique experience on a recent cruise with my sister. We went to the Viking Crown Lounge as we were leaving port in St. Thomas at sunset. We got to see everything as we left and sailed away, right at sunset, as the lights then began to come on back across the island. That experience was amazingly beautiful enough, but then we had an unexpected bonus. The captian came on the PA to tell us all that we were about to pause and do a 360 degree turn in place to set our compasses. We sailed far enough from port to get an amazing view, but were still close to shore with the lights twinkling on land. We stopped in place and the ship turned to the four points of the compass and paused at each of the four points for a couple of minutes. We got a 360 view with pauses and it was awesome. Then, we cranked up and sailed onward. The captain said they just have to do this function rarely. I wish I knew how to know what dates a cruise ship was carrying this function!!!! I would book for that experience again. It seems like a "rare in a lifetime" unexpected event on a large cruise ship. :) Anyone else ever experience such? Stories? I know they try to spin in the Alaska bays when visiting glaciers - I have experienced that, but never a complete circle with pauses like the St. Thomas night. In the glacier bays my memory was they went in, spun 180, and then went out.

 

At the Glaciers in Alaska I´ve always had at least one full 360° turn, sometimes more than one before heading out again.

[Viv0828]

That's very interesting. We have a hand held GPS that we use for geocaching. Every once in a while we have to do 2 360 turns to recallibrate it.

[VillaHappy]

I learned something new today!

[windjamming]

What an amazing experience that must have been! I remember being mesmerized by the lights in St. Thomas during sailaway on a Thanksgiving cruise, so I can only imagine how beautiful and special it must have been to do a full circle.

 

On our Brilliance cruise Captain Zini also did a 360 around Mt. Etna, and on the Radiance, the Captain (sorry, I forget his name) also did a 360 when we passed Kilauea.

 

Both of these were late at night, and any lava/eruption was at a distance. Still exciting but not the same as St. Thomas at sunset.

 

I believe years ago the Serenade would also do a 360 leaving St. Lucia, to give folks a view of the Pitons.

Edited July 13, 2013 by windjamming

[AussieVisi2r]

I've been on board for a compass set.

You are correct - it was great. Mine was off NZ on Radiance.

 

Raina

[Ocean Boy]

I believe years ago the Serenade would also do a 360 leaving St. Lucia, to give folks a view of the Pitons.

 

That is correct. Then Capt. Stig would "park" Serenade right between the two Pitons for a bit and let folks take in the scenery and the sunset. It was a great experience that I still remember well all these years later.

[jrljel]

That is correct. Then Capt. Stig would "park" Serenade right between the two Pitons for a bit and let folks take in the scenery and the sunset. It was a great experience that I still remember well all these years later.

 

WOW! That's great! I don't remember having the privilege of seeing this when I was last there on Adventure. Bummer. Maybe next year when we do it again. GREAT info that I knew nothing about! THANKS all.

[cruzer52]

The serenade is one of my family's favourite ships and my dad used to rave about the 360 turn at the pitons. At one of the Crown and Anchor meet the captain parties, my father asked the captain why they no longer do it.

 

The captain replied that while it was one of his favourite maneuvers to do, he was told by the highups at RCI that he was not to use extra fuel to perform this extra maneuver...kind of a shame if you ask me :(

[ehfl]

This is standard practice for regular compasses, and is probably done every few years. This will also correct fluxgate compasses, although sometimes there are two 360s, one clockwise and the other counterclockwise.

[createcolorfun]

how can you find out if the ship your on will be doing the compass reset?

[Clarea]

how can you find out if the ship your on will be doing the compass reset?

You could ask Guest Services who would pass the question on to someone on the marine staff.

[truffles2]

I had to do this to the compass in my car. The compass failed and the instructions said to find a large parking lot and drive in a circle. Fortunately when we exited the interstate, the exit was a big circle and the compass reset itself:p.

[enidcruiser]

We do check the compass in our plane once in a while.

We go to the "compass rose" on the airport, point the nose to each of the directions to check our in-plane compass for deviation of deg. off the actual direction. Very interesting to do this.

Guess this sort of thing happens in all sorts of transportation.

Learn something all the time on CC.

[Ocean Boy]

The serenade is one of my family's favourite ships and my dad used to rave about the 360 turn at the pitons. At one of the Crown and Anchor meet the captain parties, my father asked the captain why they no longer do it.

 

The captain replied that while it was one of his favourite maneuvers to do, he was told by the highups at RCI that he was not to use extra fuel to perform this extra maneuver...kind of a shame if you ask me :(

 

Serenade also used to do a less direct route back to San Juan in order to sail by various islands along the way. As we went by each island Capt. Stig would announce the name and give a brief history of the island. He even brought us off of Montserrat and gave us an incredible view of the destruction that the volcano did to the town there. It was on of the most memorable sea days that I ever had.

 

RCI put an end to all of that too in order to cut down on fuel use. Unfortunately, they cut out highlights of the trip in order to save some money.

[Aquahound]

how can you find out if the ship your on will be doing the compass reset?

 

Doubtful. Swinging the compass is a necessary routine, but I doubt anyone you could actually call would know when it is being done, or even what it is for that matter.

[Capt_BJ]

the traditional term: swinging the ship

 

http://www.compassadjustment.com/#4

 

Swinging the compass, or swinging the ship (as the operation is sometimes more accurately called as the ship swings around the compass card which, ideally, remains pointing north), involves taking the vessel to a suitable location in open water with plenty of room for maneuvering. With the vessel steady on each of the eight primary compass points, existing compass headings or bearings are compared with what we know the actual magnetic headings or bearings should be, the difference being the deviation.

 

During the process, any magnetic fields, created by the ship's structure, equipment, etc, which cause the compass to deviate are reduced or, if possible, eliminated, by creating equal but opposite magnetic fields using compensating correctors. These are placed inside the compass binnacle or adjacent to the compass:

 

•Magnets are aligned fore and aft and athwartships to create horizontal magnetic fields to compensate for the permanent horizontal components of the ship's magnetism.

 

•Soft iron correcting spheres or plates and the Flinders bar compensate for the induced magnetism caused by the effect the earth's magnetic field has on the ship's magnetism.

 

•Heeling error magnets compensate for the vertical component of the ship's magnetism.

 

The timing and logistics of this operation are often governed by the tide, the weather and other vessels in the vicinity. The time it takes to swing and adjust the compass is also influenced by the condition and accessibility of the compass and correctors, the manoeuvrability of the vessel, the skill of the helmsman and the complexity of, and reasons for, the deviating magnetic fields involved.

 

On successful completion of compass swing, a table recording any remaining residual deviation and a statement as to the good working order of the compass will be issued. A current deviation card / certificate of adjustment is a legal requirement on all sea going commercial vessels.

 

 

****

adjusting the compass is a skill not commonly found today and there are folks who specialize in this service. For example.

 

http://www.schenker.net/compass/

 

 

Mainstay Systems, Inc.

 

Marvin L. Schenker

Marine Compass Adjuster

Captain, USN (Ret)

Licensed Master, USCG

[philnpen]

Coming back from Cozumel our captain must have done this manuver. I remember walking down the hallway towards my cabin late at night and kept bouncing off the walls. It must have been the ship going in circles that threw off my stroll. He must have doen it again when I went to bed because the ship seemed to rotate again.

[LoyalRoyal 1973]

What an amazing experience that must have been! I remember being mesmerized by the lights in St. Thomas during sailaway on a Thanksgiving cruise, so I can only imagine how beautiful and special it must have been to do a full circle.

 

On our Brilliance cruise Captain Zini also did a 360 around Mt. Etna, and on the Radiance, the Captain (sorry, I forget his name) also did a 360 when we passed Kilauea.

 

Both of these were late at night, and any lava/eruption was at a distance. Still exciting but not the same as St. Thomas at sunset.

 

I believe years ago the Serenade would also do a 360 leaving St. Lucia, to give folks a view of the Pitons.

 

That is what I wanted to hear - other instances. Wow, a bet doing that at night near volcanoes ia amazing.

[Ocean Boy]

Doubtful. Swinging the compass is a necessary routine, but I doubt anyone you could actually call would know when it is being done, or even what it is for that matter.

 

I have a question for you that has nothing to do with the subject but I know you are watching this thread....

 

Can you explain the rules for ships using their AIS? It seems like some ships always transmit and are easy to track while some almost never transmit. Is it totally at the captain's discretion? What would be reasons for not transmitting? Thanks for any enlightenment.

[Aquahound]

I have a question for you that has nothing to do with the subject but I know you are watching this thread....

 

Can you explain the rules for ships using their AIS? It seems like some ships always transmit and are easy to track while some almost never transmit. Is it totally at the captain's discretion? What would be reasons for not transmitting? Thanks for any enlightenment.

 

Absolutely. Actually, rather than type it all out, here is a link to the USCG Navigation Center. These rules apply to vessels operating in the navigable waters of the U.S. Enjoy. :)

 

http://www.navcen.uscg.gov/?pageName=AISCarriageReqmts

[Ocean Boy]

Absolutely. Actually, rather than type it all out, here is a link to the USCG Navigation Center. These rules apply to vessels operating in the navigable waters of the U.S. Enjoy. :)

 

http://www.navcen.uscg.gov/?pageName=AISCarriageReqmts

 

Thanks very much! So would it be correct to say that a ship is required to transmit unless ...

 

1. It is under some sort of security threat

 

or a foreign flagged vessel that...

 

2. It is not departing from or destined for an American controlled port

 

3. It is in transit in American controlled waters?

 

I was wondering about this as when Independence was sailing out of Ft. Lauderdale it was almost impossible to ever find the ship anywhere whereas I could find Adventure almost all the time.

Edited July 13, 2013 by Ocean Boy

[MsGal]

Learn something all the time on CC.

 

Yes, I do, too. This is an interesting thread! :)