Sail & Motor Cruising


Being creative with tides


While RYA training schemes have evolved over the years to cover many eventualities, with courses delivered in almost 50 countries, there will always be influences over conditions which cause local anomalies. Vaughan Marsh, RYA Chief Instructor for Sail Cruising, explains how to use local conditions and imaginative explanations to convey the theory and practice of tides, wherever you are.


I


f you take a course in South Africa, you are likely to understand heavy weather sailing, as 35 knots and significant swell is commonplace in the summer months. If you take the course in the Mediterranean you will certainly know about Med mooring and may have operated in areas with little movement of water – unless you are somewhere like Venice with significant tidal streams. The ability for students to choose a training area which may match or be completely different to their usual cruising area is a good thing. But the concept of having separate syllabi for courses in tidal and non-tidal waters has become dated. As a fellow instructor, I wanted


to share some ideas for how to approach teaching the Day Skipper and Coastal Skipper courses once we no longer differentiate tidal from non-tidal courses. Before we dig into this, it’s


worth clarifying what is actually happening. The tidal and non-tidal


4 |


syllabi will be combined to ensure students receive exactly the same content regardless of where they take their training. So, no matter where a student completes their practical course, they will have instruction and the opportunity to discuss and, where possible, practice the following boat handling skills in moving water: » passage planning and passage making in tidal areas


» the intricacies of Med mooring » when anchoring, manoeuvring alongside or onto buoys, students are able to assess the elements and select the correct approach and sail plan.


This change only affects the Day Skipper and Coastal Skipper practical syllabi. Qualifying mileage for Yachtmaster Coastal and Yachtmaster Offshore exams remain with the requirement for 50% of the mileage being in a tidal area. An area is deemed tidal if published stream, current or tidal range data is available, the influence of which is significant enough to require the effects to


be taken into account to plan and execute a safe and efficient passage. Now we will look at how an


instructor at a current non-tidal centre might cover the elements that previously only existed in the tidal syllabi. Conversely this is relevant to instructors at tidal centres who need to understand what students are being asked to do at other centres. There are two clear elements that need to be addressed: heights and depths, and streams and currents.


Heights and depths Imagine entering a small harbour in the Mediterranean. The charted depth gives you 0.5m under the keel. There is a high pressure 1032 over the top of you and there has been an offshore gale for the last three days, now moderated to a 6. Would you enter with confidence? Hopefully you would be cautious as you would fully expect the sea level to have reduced. This is important for students to know


regardless of where they are taught. Tidal heights is a more


predictable change, that can be covered theoretically and is just as important for all students to know. Students should have the necessary knowledge to work out tidal heights prior to the course, but during the course must cover the elements of standard and secondary port calculations relevant to the particular course being delivered. The student needs to know


how to calculate what the expected depth will be at the given place and time. They should also be able to take into account the depth of the vessel, any offsets that have been set into the vessel’s instruments, how to check them and then complete exercises to confirm understanding. Key to reinforcing this is ensuring that any passage plan is reviewed with the question: are there any tidal or other sea level factors that we need to take into account?


www.rya.org.uk


© alextyrrell.co


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25