Frostbite Series

Last Saturday, conditions by the 3 pm start time were very reasonable and the racing was held in a modest force 2 - occasionally 3 - south westerly, with very mild air and some glimpses of the sun. Not at all bad for the last day of October!

Whilst the conditions may have been ready for the start not all the competitors were and the prompt commencement of the first race in order to finish everything before it got dark, did leave certain boats still on shore!

The final total of eight boats for the two races was however very satisfying for an end of October frostbite race.

The races were sailed round temporary pillar buoys in order to make a more appropriate course for the conditions and the time available.

For a short while two simultaneous courses were being sailed as the OOD on the start line was using the pillar buoys and rescue out on the course was assuming the use of the conventional marks !

However, this was soon resolved amicably and a good chase was on. No protests were received over the bar at the end of the afternoon so all was well. Finishing positions after handicap were: 1. Keith Jones (Laser); 2. Paul Johnson (Solo); 3. Twm Harrison (Topper); 4. Chris Bannister (Magno); 5. Sarah Boorman (Laser Radial).

It was good to see Trevor Smith out on the water again in the RIB and many thanks to him for helping provide safety cover and for some useful advice to Mark Jones to help him get used to his newly-acquired Graduate.

The second race was largely 'more of the same' with some pleasant and not too arduous racing. The results were: 1. Peter Bower (Phantom); 2. Paul Johnson; 3. Keith Jones; 4. Sarah Boorman; 5. Chris Bannister; 6. Twm Harrison.

Cruisers

The cruisers are now mainly out of the water and back up on the 'hard' ready for all the winter maintenance and off-the-water work that is part of the pleasure.

Gardeners have the 'garden shed', DIYers have the 'workshop' and cruiser owners have the 'boat' to nip out to for a bit of relaxation and the odd refreshment under the guise of necessary work and maintenance. It's all part of the hobby!

Next Sailing Events

The next Frostbite racing is in two weeks on Saturday, November 14, with two races starting at 3 pm.

Annual general meeting

Further reminder for all full members to attend the annual general meeting at 2 pm on Sunday, November 22. Do please make a note in your diary and come and participate. Your views and ideas on the club will be welcome in the open discussion.

Nautical Nips

One of the most confusing topics, even to mariners, is the measurement of depth of water.

Landlubbers and habitual lake (including Mediterranean) sailors are often confounded by the enormous effect of the tides on sea level.

Here at Saundersfoot on the edge of the Bristol Channel, this effect is amongst the largest in the world with differences in the height of water of over eight metres (26-feet) between high and low tides. This gives rise to quite a large number of different possible measurements of depth according to what the tide is doing.

The avoidance of confusion is obviously pretty important, e.g. not ripping the bottom out of the boat, to ensure that one can get back into harbour, to avoid going aground, to protect the propeller or to have enough anchor chain to moor-up, etc.

All charts (the name for maps of the sea) base their information relating to objects in the sea on what is known as chart datum.

This is the lowest level to which the tide normally ever falls at the specific port to which the chart refers - exceptionally there can be even lower tides owing to combinations of wind, pressure and tide, but these cannot be predicted so are not used.

The charted depth of the sea floor shown on the charts is the depth of the floor below datum, and the height of the tide at any particular moment, is the depth above datum. The parts of the sea floor (or other objects such as wrecks, etc.) that protrude above datum but are submerged at other times of the tide, are marked with a 'drying height' which is their height above datum.

Thus to determine whether a feature, e.g. seabed, rock, sandbank, wreck, etc. is likely to be a relevant danger, it is necessary to calculate the exact state of the tide over chart datum and relate this to the depth of the object below chart datum or its drying height.

You may already be lost in this explanation and it is therefore obvious why mistakes are sometimes made as it is far from simple!

To add to the complexities, tide heights in tide tables are only given for the exact times of high and low water for specific places. Heights at other times of the day or for other ports have to be calculated.

When the moon has most gravitational effect (at full and new moon) we get the highest and lowest tides which are called spring tides, whilst the smaller tides at other times are referred to as neap tides.

The difference between high and low tide is the tidal range. The height of land-based objects on a chart, e.g. lighthouses, cliffs, etc. are measured above the height of the average (or mean) spring high tides at a particular port and this calculated level is called mean high water springs (MHWS).

If you have got this far through this explanation you have done very well - I did say it confused even mariners. The most practical conclusion is to go to sea only with someone who really knows what they are doing! i.e. join the club!

 Skipper's Mate