Attached as Appendix B are some notes I wrote a few years ago giving acronyms (well two out of three) to some course setting concepts – STAD, EaRWiG and DAD. I’d like to introduce one more – SCIF standing for Start, Course, Interval and Finish. These are, by stint of the RRS, the main areas of responsibility allocated to a RO – the start, the course, the interval (duration) and the finish – SCIF.
Historically the start line has been from the Platform with the only change being made after a problem in the 1976 race since when the fixed outer end Mark D has been replaced by a movable ODM. However, there are other problems with the historic Platform starting line the primary ones being: –
a) The difficulty in setting a start direction in the arcs from about 220° through north to about to 70° and about 150° through southeast to about 180°.
b) The closeness of the line to the River entrance and possible interference with other users.
c) The depth on the line at certain tides.
d) The depth of water to the west of the River.
Problem a) is not that major as a reaching or running start has been generally thought to be acceptable for the race.
Problem b) is of concern and has on more than one occasion impinged on the race. Our current starting time is 10:10. The ferry time table includes a 10:00 sailing and it takes an outgoing ferry about 12 minutes from Lymington Pier to be abreast the Platform. If only two ferries are in use the incoming ferry is likely to pass the Platform some 5 minutes after the outgoing ferry. Given that ferry timings are variable (in 2020 the outgoing ferry was late and there was no inbound ferry) a 10:10 westbound start can be delayed by ferries for anything up to 15 minutes.
Problem c) The inner end of the Platform line has a charted depth of about 2 metres above datum. EAGER, a 2020 entry, has an IRC certificated draft of 2.62 metres.
Problem d) When the wind is in the north or south and particularly when light the difficulty in setting a windward leg on the north shore to the west of the river tends to compel an east going start which may not be tidally desirable. This was the case with the 2020 race. Move the start just some ¾ mile to the east of the River and this problem would go away.
An alternative to a Platform start could be a Committee Boat start. Such would make it possible to avoid much of all the above Platform start problems and also lead to more course options e.g. a southerly first mark. It would also remove the need for Race Team transfers to and from the Platform which would improve safety. A downside to a Committee Boat start would be the sourcing of a suitable boat, a power cruiser of 40 ft. length or more.
Building a new platform off the entrance to Pylewell Lake would solve most of the problems.
Changing the start time would solve problem b).
Conventionally most races start and finish with a beat and hence require a windward and leeward mark. This is the simplest of courses – a sausage. But a sausage course (particularly on an east west running tidal shore) can advantages some yacht designs over others e.g. symmetric vis asymmetric spinnakers. A third mark offset from the first mark can be used to force a reach and square up a run and equalise some of the design differences. So the simplest course for the race in our waters would tend to be a triangle.
The Potter Ship race has always been based on laps. Historically this was two laps often shortened to one but with the ALR, as its name suggests, there has to be laps and the more the better. In both of these cases the lap starts and finishes at the same line/gate i.e. the start and finish of each lap.
With our fixed marks the shortest length triangle that can be set from the Platform is likely to include E, F and C marks (0.65, 0.45, 1.15 and 0.6 = 2.85 NM). Using STAD (Appendix B) and the table in the RRS (page 200) the time for slow and fast(ish) boats in different winds speeds to complete this lap would be: –
||5 metre boat
||9 metre boat
|Wind speed (kn)
||Lap time (h)
||Lap time (h)
Interestingly in the 2020 race with much the same triangle course the elapsed average lap time for the slowest boat was 1 h 49 mins (1.8 hours) and for the fastest 54 mins (0.9 hours).
Further observations on courses are to :-
- Avoid shallow marks (DAD)
- Try to apply EaR-Wig which can be difficult in low winds as there is not opportunity to set a short north/south leg to the west of the Platform owing to depth constraints.
- The SIs need to prohibit boats from passing through the Gate the wrong way.
The Interval or Duration
The above tends to suggest that for all competitors to finish the race in a 5 kn wind with the current target time of 2 to 2½ hours (the interval) the course lap length for an AALR needs to be about the 2.8 NM or not much more (up to 3.3 NM).
have finished in 1 hour 58 minutes and the last boat would have timed out. With the ALR this year all boats finished, the first boat in 1 hour 58 minutes and the last in 1 hour 59 minutes.
An alternative to “short” lap lengths could be to increase the target time (interval). Not only would this improve course opportunities in low winds it could be used to increase the number of laps and hence, with ALR, lower the finishing time span in higher winds. Okay bar opening hours might need to be changed to retain the same profitability together with having a later luncheon or we could just agree to race some more like we used to with this race.
Since the 1960s when a competitor “bumped” the ferry whilst finishing at the club the finish has been at the Platform. Whatever the case, Handicap or ALR, Platform or Committee Boat, start the finishing line needs to be at the same point in the lap as the starting line.