New RYA training charts - Time zones - rant

slaptop

New member
Joined
9 Feb 2017
Messages
4
Visit site
Came here because i got mightily confused about the timezones of the RYA ecosystem charts. It's a small world.
Anyhow.
In case others come across this thread...i came across this...Can't vouch for it yet.

RYA Chart Area Time Time Zone Country equivalent
Northern Territory UT 0000 UK
Northern Territory Daylight Saving Time UT + 1 0000 UK - BST - Summer Time
Southern Peninsula Standard Time SPST UT + 1 - 0100 France - French Standard Time
Southern Peninsula Daylight Saving Time SPDST UT + 2 - 0100 France - French Summer Time

So I've included the above in case this link disappears over time.
TIME ZONES | RYA NAVIGATION COURSE
 

bdh198

Active member
Joined
28 Sep 2011
Messages
358
Location
Solent
Visit site
What...? A twelve and a half year old thread revived by someone who has been a member for three and a half years, but has only now posted their first message?

Looks very suspicious and I won’t be clicking that link.

edit: “thread” not “threat”!
 
Last edited:

Skysail

Well-known member
Joined
30 Sep 2004
Messages
1,149
Location
Victoria BC
www.skysailtraining.co.uk
What...? A twelve and a half year old threat revived by someone who has been a member for three and a half years, but has only now posted their first message?

Looks very suspicious and I won’t be clicking that link.

Don’t worry, the link is quite OK. It is my website!


I don’t know why the thread is active again.
 

Daedelus

Well-known member
Joined
11 Jun 2006
Messages
3,689
Location
Hants
Visit site
Some years ago I was wanting to go from Cherbourg to Guernsey and was using Reeve Foulkes which relate to tidal times on Cherbourg in UT-0100. (It's time zone -0100 as that is what you apply to the time to get UT). I then wanted to know during what times I could enter the inner harbour and the almanac refers you to HW+/- whatever but then you find that Guernsey works on UT and is referred to HW Jersey. To calculate the best time to leave Cherbourg I referred to the almanac again which said something like 4 1/2 hours before HW Dover (UT). At this point my brain exploded and Mrs D said there, there, wandered off and returned saying I've bought another night at the marina and I've got some nice things for lunch and a decent bottle of wine. (God I love that woman).
After lunch and a cafetiere of coffee I drew up a table into which I put the various times and cracked the whole thing in 10 minutes (which included time for deciding on the table structure.
Now that I teach the subject I have a lot of sympathy and I allow a bit extra time to get it very clear and sorted and it is the bit that students struggle with. However, provided they don't throw their toys out of the pram they generally crack it as the SPDST on the RYA charts corresponds to summer time in France if you are coming from the UK. I was at one conference where a harassed instructor asked if this particular element could be dropped and the RYA head honchos said they sympathised and understood but they needed students to have some idea of working things if they crossed to France from the UK or CI times zones.

I once left the ships clock on UT in summer time and we were all horrendously late as a female member of the crew was well over an hour late in getting ready to come ashore for dinner and said she thought the clock was on local time. (The other crew member was nearly biting my leg he was so hungry).
 

slaptop

New member
Joined
9 Feb 2017
Messages
4
Visit site
What...? A twelve and a half year old thread revived by someone who has been a member for three and a half years, but has only now posted their first message?

Looks very suspicious and I won’t be clicking that link.

edit: “thread” not “threat”!
What can i say. Everybody's unique. I'm different.
Started sailing in my mid 30's. 1988 Stopped by divorce,
restarted a number of times since.
1995 stopped by marriage to H2O-phobe, stopped again by son's birth, 2002 too non-bendy for darts and dinghys did comp crew sailed OPBs for a couple of years, stopped by my son's chronic illness, 2007 Day skipper lots of day sailing bang! son goes into 5 month coma and i lived in hospitals and rehabilitation hospices for two and a half years, since then work from home because he needs two carers. Had to shelve everything sailing and not think about it. 2014 stopped work. 2016 I'm 62 and determined, restarted sailing again with a fractional outfit, respite (from 24/7 caring) daysails. Wife doesn't support this idea, multiple hospital stays with my son because he is now severely disabled and has no language. Continue to daysail when we're discharged. 2017 I'm now 63 still bumbing along the bottom of sailing. Wife informs me my sailing is unacceptable. (strange agreement with my crew) we live completely separate lives co-caring.
2019 next to him critical in hospital again, get solicitor's emailed letter wanting "mutual divorce" (reason ...I do my own laundry!). I Agree. Have last Xmas with son at home before divorce progresses. January he's critical again, divorce still on pause. February I'm back sleeping next to a ward bed in hospital overlooking Brighton Marina. 5 weeks of beautiful sailing days later we discharge because Covid is encroaching the ward and my son is immunosuppressed. I saw 3 men die on this outing 2 of them only had me with them. LOCKDOWN where everyone in the country joined my constrained isolated world.
Followed by SHIELDING, virus still out their, son still immunnosuppressive. I still can't sail.
Do a distance learning Coastal Skipper.
Hence my first post took 3 years. Hence my 5011 is from 1989. Hence my perennial learner/relearner mode. Hence my general misfitted-ness.
Watch this space.
 

Airscrew

Active member
Joined
1 Feb 2015
Messages
241
Location
Hamble River and Nidri - Ionian
Visit site
Here we go again.
Years later, this is still not clear to many of us, and not a surprise to you!!
So please have some patience.

Doing my YM theory soon.
Im trying to create a little 2x2 reference table for myself.
I see that the RYA 'appear' to have inverted the time adjustment, according to the 'non-sailing' viewpoint.
(ie France is 1 hour ahead, but is Z-1 in 'RYAthink').

Is this model (below) valid for the RYA/YM exam??

Northern Territory = NT

NTUT = UT_______________SP (is also though of as or called Z-1)
(say 1200hrs)_____________is 1300 there (Sp is 1 hour ahead, -1 to get back to UT)

DST (inNT)________________SPDST (DST in SP region)
ADD 1 hour in____________use -2 to get back to UT
almanac to get
local time (DST)
BUT
use -1 to get back
to UT

Sorry for the formatting limitations here.

Is it 'safer' / less error prone (for the exam) to do all the calcs in UT (example in reference to the tidal diamonds/ computation of rates based on VIC tables/tides), then convert to DST or SPDST (local) as appropriate??

Please point out any errors / misunderstandings I may still have.
Many thanks.
 

Sandy

Well-known member
Joined
31 Aug 2011
Messages
20,806
Location
On the Celtic Fringe
Visit site
I don't know if this helps but is what I do in the real world.

Boat time is always UTC, no matter what time zone I am in. In the summer it saves all that faffing about with adding an hour to tide tables. The sun rises and sets and does not worry about time zones.

I convert everything back to UTC, e.g. CET tides get changed to UTC, calculations done in UTC and if needed converted back to local time.

This summer on a trip from Portugal, in BST, we stopped off in Spain and France, CET Daylight saving Time, then back to the UK on BST. Several crew members got very confused moving time zones, but a quick look at my watch and the addition of one or two hours was easy.

To quote Ford Prefect in The Hitchhiker's Guide to the Galaxy by Douglas Adams, 'Time is an illusion. Lunchtime doubly so.', which sums up the confusion I felt when doing my YM Theory. I saw familiar names and stretches of coastline that they had moved about thus confusing my few remaining brain cells.
 

capnsensible

Well-known member
Joined
15 Mar 2007
Messages
42,927
Location
Atlantic
www.herculessailing.com
It's never too late for a zombie thread.

On both DS and Coastal courses, there is a good explanation on page 3 of the course question book.

This is another page usually titled' stuff that students never bother reading'.

Soo knowing this and knowing students, I always spend around ten minutes in hour one of day one helping people to get it. Saves loadsa....time later in the courses. :)
 

Daedelus

Well-known member
Joined
11 Jun 2006
Messages
3,689
Location
Hants
Visit site
If doing tidal streams it doesn't seem to matter when you convert to "correct" time (ie UT if in UT zone and it's winter, UT-1 if in SP and it's winter and so on).

HOWEVER, if wanting to apply differences for a secondary port in depth calculations then it is important that you use local "standard time" ie don't apply correction for summer time, but if in SP do use SP time (Zulu -1) as the times given in the difference table relate to the local "standard" times. Look at a table for a) northern territories and b) SP to see what I mean.
 

Seven Spades

Well-known member
Joined
30 Aug 2003
Messages
4,700
Location
Surrey
Visit site
Not sure I agree....

We always run the boat on UTC (or GMT as I prefer to call it), and it doesn't seem to cause any problems..... ships clock is left on UTC, my watch remains UTC, SWMBO changes her watch to LT, and generally, we work it out.... its takes all of a few mins for us to get it straight in our head what the time difference is between UTC and LT (adjusted for DST as appropriate).... and avoids major stupid mistakes with the navigation....

I'm not sure how we'll do it when the time difference becomes a bit more significant though... suspect i'll change my watch to LT as well, and just leave the ships clock on UTC.... time will tell.../forums/images/graemlins/grin.gif
I used to do exactly this but now we are in the Med we have moved everything to local time.
 

Daedelus

Well-known member
Joined
11 Jun 2006
Messages
3,689
Location
Hants
Visit site
The table below shows one way of working it all out.
Start with tide table and look up HW at Hamilton in Zone -0100 time. In local (summer) time it will be in 4th column.
Then convert to UT to work out what the tide is doing. HW Victoria is 0408, so 0504 is (near enough) HW +1 which you use on tide tables.
No charge for using the table. (I might add it's imilar to the one I drew up when confused by too many time zones and toom many HW Dover +3 1/2s and HW Cherbourg -2s.
1674384708485.png
 

RunAgroundHard

Well-known member
Joined
20 Aug 2022
Messages
1,305
Visit site

A quick question. The chart in the link shows the time zones where - is east of prime meridian and + is west. So far, all other charts that I have found on google show + east of the prime meridian and - to the west. There are even maps with just 1, 2, 3 to the east and west with no arithmetical operator.

I have always understood the chart in the link to be correct i.e. - to the east of the prime meridian. Is there a standard for time zone notation?
 

capnsensible

Well-known member
Joined
15 Mar 2007
Messages
42,927
Location
Atlantic
www.herculessailing.com
Sailors, knowing that the sun rises in the east, sets in the west and is overhead at local noon set the gold standard.

When that happens before Greenwich, is minus. After Greenwich, plus. So Greenwich is the datum and we adjust to that.

Others, such as travel agents and politicians may disagree. Until they learn to navigate boats. :)
 
Top