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  • Neaping Question

    Hi, does anyone have any step by step process on how to solve a neaping question. I have some notes but they're not detailed enough for me to get it. It looks fairly straight forward but the example doesn't seem to relate to current tidal data and not been supplied with extracts from tide table to figure it out. If anyone have a step by step process or can direct me to a website with an explanation that would be great. Thanks.
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  • #2
    I never did a neaping question at college, but given that you'll be wanting to get out of the port in as few days as possible, then you'll be aiming to get over the obstruction at high tide. Just see which tide in the table is high enough, surely? I didn't do SQAs though so they might want a less sensible/practical way of solving it

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    • #3
      I never did a neaping question at college, but given that you'll be wanting to get out of the port in as few days as possible, then you'll be aiming to get over the obstruction at high tide. Just see which tide in the table is high enough, surely? I didn't do SQAs though so they might want a less sensible/practical way of solving it

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      • #4
        Then you realise that tidal predictions are highly subjective and can be over 50cm below prediction and that the current can run in the opposite direction the tide... Therefore its all theoretical. Sorry, not a productive answer.

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        • #5
          Originally posted by YoungMariner View Post
          Then you realise that tidal predictions are highly subjective and can be over 50cm below prediction and that the current can run in the opposite direction the tide... Therefore its all theoretical. Sorry, not a productive answer.
          So what the heck is the point in doing them in college then? Apart from getting a guesstimate, and apart from the old 'just cos the MNTB and MCA says you do' excuse? Does anyone actually use them in a practical manner?

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          • #6
            I can think of a few people who had wished they’d understood how tides work, caught a few out here. Can be quite expensive, and or a very lengthy wait.....

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            • #7
              Originally posted by Midge View Post
              I can think of a few people who had wished they’d understood how tides work, caught a few out here. Can be quite expensive, and or a very lengthy wait.....
              I have no issues with learning about tides and understanding how they work. I'm obviously not saying I'm not going to learn about them, but my moan was about why use subjective predictions (as quoted!) for tides? Is there not a better way to do/learn them? Does everyone else just use the total tides programme onboard?

              You can tell that I have exams coming up....lol.

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              • #8
                Oh my, no idea I’m a parent lol I just use tide tables, but am aware of air pressure and it’s effects on tides , as I had various obstacles where state of tide makes a difference between looking a numpty or not, heaven knows what you lot use with your new fangled electronics and programmes!
                Good luck with the exams though!

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                • #9
                  Originally posted by riker View Post
                  Does everyone else just use the total tides programme onboard
                  Yes.

                  I've not done a manual tide calculation since I was a cadet. As with a lot of the syllabus you have to learn the theory but when you are qualified you'll probably never do it. Same with celestial, using paper charts etc. You still need to know the principles behind everything though.

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                  • #10
                    Originally posted by riker View Post

                    So what the heck is the point in doing them in college then? Apart from getting a guesstimate, and apart from the old 'just cos the MNTB and MCA says you do' excuse? Does anyone actually use them in a practical manner?
                    There is no accounting for why the MCA and MNTB ask you to do these things! I had to learn about King Beams and Queen Beams and the rotation of canvases as well as which direction you drive the dogs home on a hatch cover, how to box the compass in 1/2 points as well as the equipment in a lifeboat equipped with sails and oars, (which we had to do around the flipping docks in Liverpool before they became sanitary), despite the fact I never sailed with any of the above, was ever likely to sail with them or ever use the knowledge again....

                    I just think the MCA wanted to train us in case the ships ever sailed through a time warp and we would use those skills again.... or maybe it was just because they did not want to enter the 19th century - let alone the 20th century!
                    "Any damn fool can navigate the world sober. It takes a really good sailor to do it drunk." - Sir Francis Chichester.
                    "Waves are not measured in feet or inches, they are measured in increments of fear." - Buzzy Trent

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                    • #11
                      Originally posted by riker View Post

                      I have no issues with learning about tides and understanding how they work. I'm obviously not saying I'm not going to learn about them, but my moan was about why use subjective predictions (as quoted!) for tides? Is there not a better way to do/learn them? Does everyone else just use the total tides programme onboard?

                      You can tell that I have exams coming up....lol.
                      A subjective prediction is better than no prediction at all, and you'll find that most of the time the tidal predictions are reasonably accurate. This is why UKC is an important safety factor in everything we do. If a charterer asks you to go to a certain port and you're going to get neaped while you're in there, they will want to know what is the earliest/latest guess for when you could get back out again. Just because we use a computer to do the maths for us doesn't mean it's not worth knowing, if only to have an understanding of how reliable or not the entire process is. You would be astounded at the number of people that will believe that the current will be 1.43kn because a computer displays a number to two decimal places...

                      Everything we do is based on calculating as precisely as is reasonable and practicable, while knowing how naff the source data is. If you're peed off at tidal calculations being off by 50cm then perhaps you shouldn't look at the source diagrams or CATZOCs on your charts/ECDIS... Even CATZOC A corresponds to a depth accuracy of within 50cm +/-1% of depth.

                      I enjoyed your rant though Good luck with your exams

                      Comment


                      • #12
                        Originally posted by Midge View Post
                        Oh my, no idea I’m a parent lol I just use tide tables, but am aware of air pressure and it’s effects on tides , as I had various obstacles where state of tide makes a difference between looking a numpty or not, heaven knows what you lot use with your new fangled electronics and programmes!
                        Good luck with the exams though!
                        Haha no worries Midge! Thanks for the good luck!

                        Originally posted by EH75
                        Yes.

                        I've not done a manual tide calculation since I was a cadet. As with a lot of the syllabus you have to learn the theory but when you are qualified you'll probably never do it. Same with celestial, using paper charts etc. You still need to know the principles behind everything though.
                        Yeah. I suppose the academic side IS there to teach you about the foundations and principles behind it all. I think it's just that the MCA/MNTB rattle my cage a bit though, along with the general state of training/opportunities/quality for Cadets. An officer I know told of horror stories whilst onboard on his sea phase (could have had fatal injury's from idiot senior officers orders! Lucky he refused but someone else might not have!) and his training provider essentially brushed him off when he complained and they 'couldn't find' his complaints in written form when he challenged them again about it later on. That's another story however.

                        Originally posted by Hatchorder
                        There is no accounting for why the MCA and MNTB ask you to do these things! I had to learn about King Beams and Queen Beams and the rotation of canvases as well as which direction you drive the dogs home on a hatch cover, how to box the compass in 1/2 points as well as the equipment in a lifeboat equipped with sails and oars, (which we had to do around the flipping docks in Liverpool before they became sanitary), despite the fact I never sailed with any of the above, was ever likely to sail with them or ever use the knowledge again....

                        I just think the MCA wanted to train us in case the ships ever sailed through a time warp and we would use those skills again.... or maybe it was just because they did not want to enter the 19th century - let alone the 20th century!
                        Bloody hell, I don't even know what a King Beam is or what driving the dogs home mean! How far standards have fallen eh lol! But yeah, it seems that MCA are preparing all cadets for accidental incursion into a rip in the fabric of space-time with their 'traditional methods' of academic syllabi!

                        Originally posted by HarmlessWeasel
                        A subjective prediction is better than no prediction at all, and you'll find that most of the time the tidal predictions are reasonably accurate. This is why UKC is an important safety factor in everything we do. If a charterer asks you to go to a certain port and you're going to get neaped while you're in there, they will want to know what is the earliest/latest guess for when you could get back out again. Just because we use a computer to do the maths for us doesn't mean it's not worth knowing, if only to have an understanding of how reliable or not the entire process is. You would be astounded at the number of people that will believe that the current will be 1.43kn because a computer displays a number to two decimal places...

                        Everything we do is based on calculating as precisely as is reasonable and practicable, while knowing how naff the source data is. If you're peed off at tidal calculations being off by 50cm then perhaps you shouldn't look at the source diagrams or CATZOCs on your charts/ECDIS... Even CATZOC A corresponds to a depth accuracy of within 50cm +/-1% of depth.

                        I enjoyed your rant though Good luck with your exam
                        Yeah, I get that with the just reading off a computer screen blindly, without understanding why and how etc. And yeah I forgot about them, I remember reading about the accuracy of CATZOC for ECDIS charts and what all the different stars mean and how you should interpret them on ship. Interesting stuff but also somewhat concerning when the source data is from 1840 or something lol! (If I'm remembering it correctly).

                        I suppose because I'm still a Cadet, I don't quite have the right perspective of it all; maybe when I qualify I'll have a more positive view. Plus, I don't think that being in the middle of exams, that ones mind is sufficiently clear and objective lol!

                        Thanks for the well wishes!

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