CHAPTER 9 Weather gauge and the lee shore
Apart from the possibility of being overwhelmed in open water, the greatest danger at sea is being unable to claw free of a lee shore. In the days of square rig when some ships would struggle to make to windward at all, the lee shore was always potentially deadly. For modern yachts and power craft with strong engines and close-winded rigs, it only becomes so in tough conditions. However, a competent skipper is always aware of lee shores and develops an instinctive respect for them. In heavy weather, keeping strategically out of their way is vital, lest a vessel that seems to be managing fine is suddenly disabled by an unforeseen contingency. In the absence of traffic, an instinctive skipper will always steer up the weather side of a river on a windy day, and the very idea of cruising close in to a beach with the waves breaking on it is anathema. A seamanship examiner always notes how his candidates set themselves up to deal with lee shores. Keeping well clear is known as maintaining a weather gauge.
Strategic options
When overtaken by heavy weather at sea, it is important to look at the options, prioritise, then act. Strategy will depend on the direction of wind and wave in relation to the course desired. It will also be affected by sea room and crew condition amongst other factors. However, the following options will be considered: • Continue with the passage — If things are not too severe, it may be possible to carry on regardless, taking due note of sea conditions for a motor vessel, or reefing down appropriately under sail.
• Keep to the sea and survive — The greatest danger at sea generally comes from the proximity of land. Unless the boat is likely to be thrown down by the waves she is not in any immediate danger from the water, but the land can smash her up in minutes. Once again, the main issue is the lee shore. Unless the boat is in mid- ocean and beyond reach of realistic shelter, it is often unpopular for a skipper to decide to remain at sea, but far more boats have been lost running for shelter than by staying out in open water. Keep well clear of areas of known wave disturbance, such as offshore shoals,
tide rips, or zones of high current activity typified by the Gulf Stream of the eastern US. It is also important to have studied the survival tactics that are suitable for your boat, because the time to experiment randomly is not when it is blowing so hard you have to crawl up the deck to avoid being swept overboard.
• Seek shelter — If the vessel is at risk and shelter can safely be approached, this is the preferred option. When assessing the risk of exchanging searoom for the perceived security of a harbour or anchorage, the following points may be considered:
Downwind Running downwind for shelter under sail has the great advantage that the passage will be less dire for the crew and will place less stress on the boat. Even motor craft can benefit from this to some extent, despite the high skill levels required to drive faster craft. For every vessel, however, the coast that beckons will be a lee shore with all the attendant perils. Upwind The opposite applies to an upwind refuge. Getting there may be gruelling, but by the time you arrive, you should be under the lee of a weather shore and essentially safe.
Assessing harbours of refuge If a harbour is to be attempted to leeward in storm conditions, its entrance must be impossible to mistake and wide enough to allow for any loss of control that may arise from a deteriorated sea state. Consider the way the bottom shoals. Anything sudden is likely to give rise to heavy seas just when you don’t want them. Is a river involved? If so, avoid the ebb tide because it may cut up the sea cruelly. What is the disposition of any harbour walls? Will you have to make a hard turn in the entrance, perhaps for the first time since deciding to run for shelter? If so, is your vessel going to be powerful enough? Will there be wave bounce-back from the walls? And so on.
Notwithstanding all this, harbours do exist which are genuinely ‘all-weather’. They are not common, but they are beyond price to the storm-tossed sailor. Almost any refuge that lies to windward with a sheltering shoreline behind it can be entered in a gale. The only problem is getting ‘up’ there in the first place.
MANUAL OF SEAMANSHIP | 87
Heavy Weather
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 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172
