In 1966, Doctor Jack Barnes, determined to solve the mystery, lay on the seabed weighed down with diving gear and searched the water for what he suspected was a tiny transparent creature. He found a tiny jellyfish, its bell just 2.5 cm across trailing four almost invisible tentacles. To test his theory he brushed the tentacles against his skin. For good measure he did the same with his son and a lifesaver on the beach. All three
TWO IRUKANDJI JELLYFISH
(With an Australian $2 coin)
(With an Australian $2 coin)
The irukandji's larger and better known relative, the box jellyfish, has killed 67 people in Australia since 1883 - the year of the first recorded fatality. Its sting leaves ugly welts and scars for a survivor & results in instant pain. It can kill within minutes although most victims can survive if help is close at hand. By contrast the irukandji sting leaves a barely discernible rash - likened to prickly heat, and there is no immediate pain. The symptoms which take between 20 & 30 minutes to begin resemble those of decompression, a stroke and other conditions that in the past may have been wrongly cited as causes of death.
In Australian tropical regions - less than about 25 degress South, swimming in the ocean should be done with much caution especially between October and May. Consult local authorities (State Boating Authorities, Marinas, Police, Hospitals etc) for the likely danger from jellyfish.
Regardless of the brand all the parts should be washed and the old grease removed. All springs and pawls should be checked for condition and drain holes cleaned.
* Always maintain a supply of spare pawls & springs.
* Clean and assemble as you go.
* Overhaul one winch at a time - you can always use the other as a guide when reassembling.
* Wash winches in fresh water after a voyage so that dried salt does not accumulate within.
* Use winch hats - made from a breathable fabric.
* When reassembling use an anti-corrosive grease to stop electrolysis - such as Duralac.
Prevention is better than cure. So reduce flogging by thinking ahead and positioning the boat relative to the wind so as to keep it to a minimum. Reduce chafing by ensuring that nothing sharp comes into contact with the sails. This will mean making frequent checks of mast, spreaders & stays for sail hazards. Where necessary fit chafing patches to sails in places where chafing is unavoidable. Such precautions are applicable to all sails and rigging - so don't forget about the mizzen which might not be used very often.
A pair of binoculars can be useful for checking sails for signs of trouble - as long as it is carefully done. Despite all reasonable precautions there will be times when a sail repair needs to be done quickly and for these occasions the boat should be equipped with a sail repair kit.
Basic Sail Repair Kit 10mm wide strips of sail cloth of appropriate weight (Usually 8oz) - & lots of it
2M Stickyback
5M each of 48mm, 24mm & 12mm webbing
Spare sail slides - for all sails / masts
Seaming Palm
Sailmakers Needles (many sizes and many spares)
Scissors and / or good bookmakers knife
Waxed sailmakers thread
Contact cement
The following figures give a guide
to the size of cable required for different capacities. It will be OK to run
two cables of the same cross sectional area to increase current capacity if
a large enough single cable is unavailable.
NB
Equal cable runs must be used for both positive and negative cables
Cross Sectional
Area (Sq mm)
8.5
25.0
40.0
60.0
Area (Sq mm)
8.5
25.0
40.0
60.0
Approx Capacity
(Amps)
60
170
300
415
This kind of mounted tube can also serve as part of a Dan Buoy stowage system
Lure made from a piece of copper or SS pipe
and single hook.
Lure made from coloured rope ends and single
hook
1. Limit active watches to no more than about 3 hours by night and 6 hours by day.
2. When there are more than 2 crew give each crew at least 6 hours of continuous rest.
3. When there is more than 3 crew have at least one crew on a standby / maintenance watch.
4. Unless there is more than 3 crew the skipper needs to be part of the watchkeeping roster.
5. Duty watches should not take over without a minimum handover period of 15 minutes.
Duties
Watchkeeping duties will normally include the following
Keeping the log (Wind, Sea state, Barometer, Course, Leeway, Engine readings, Sail changes etc)
Steering, Trimming & Changing Sails,
Navigating with the best possible Lookout,
Taking collision avoiding action - Helmsman must know and recognise a collision course by day and night.
(See Navigation Lights)
Keeping the Skipper advised of designated changes,
Calling for extra help in conditions specified by the Skipper.
Techniques
In good conditions during daylight watchkeepers will find the tasks much easier than when it is cold wet and / or rough at night. The first requirement is to try and keep warm and dry with the right clothing and by having any spare crew go below in rotation into relative warmth for short periods. It is better to wear several layers of thin clothing rather than one layer of thick material. Those on deck need to move about frequently - keeping circulation up by moving arms and legs vigorously and, if not practicable in the cockpit, then outside and tied on. Hot food and drink should be taken both for warmth and the physical activity required in preparation. Mental activity like navigational calculations helps maintain alertness.
Leg lengths will depend on the degree of accuracy of the estimated position - longer when this position's accuracy is degraded by time. About 10 minutes for the first leg will be about right when the estimated position is accurately known. Speed of search depends mostly on sea state and visibility conditions. Turns at the end of each straight segment are through 120°. At the end of a full pattern a new pattern is commenced with its first leg being on a heading 30° away from the one
Normally such a search would be done using the engine only - so that the most accurate courses can be steered and all available crew can concentrate on the visual search. However, when engine power is unavailable, the first leg of the search should be done hard on the wind to establish the consequent headings for the other legs of the pattern. The second pattern is still 30° away from the first and the third pattern reverts to the same as the first. The coverage will not be as evenly spread as when an engine is used but will be close to the best available consistent with simplicity - especially with a short handed crew.
Navigating the pattern is much simpler and more accurate with GPS but remembering that the visual search must not be sacrificed for the sake of pattern accuracy. An allowance needs to be made for the drift of the MOB which will be mainly with current and / or waves. Furthermore the effect of wind alone will be greater on the search vessel than on a person mostly under water. Therefore in strong wind with a high sea state the MOB drift will be difficult to estimate. Therefore the leg times might need to be increased.
When the search is being conducted soley by the mother vessel without external assistance or a homing device the chances of locating an MOB in high sea states or at night are very low. However, if the MOB is sighted it will be vital to keep him/her in sight and to have made preparations for recovery of the MOB
