Saturday 18 September 2010

Man Overboard Recovery/Retrieval Strategy for Sailboats

'Man Overboard' yelled out at the top of a crew's lungs is a sailboat skippers' worst nightmare! Even with preparation and practice, when and if the event occurs, under severe pressure and weather conditions prevailing at the time, is everything that has been practiced going to go smoothly? Most of us thankfully, have never been put in this situation, so it is impossible to predict what will happen in the event of this stressful incident occuring - hopefully, it won't ever come to pass for you.

However, it is best practice to be as best prepared as can possibly be. I recently came across this article by Marco Coda (he uses the term COB rather than MOB) and felt it is well worth repeating. Marco is a cruising instructor with many years experience and describes his preferred method here:

'The day has dawned crisp and clear, the radio is forecasting a light to moderate Nor’wester, everything promises a wonderful weekend of sailing. Two hours out of Vancouver on the way to the Gulf Islands the wind pipes up, the boat is well heeled over and everybody is having a great time. Suddenly you catch a movement out of the corner of your eye and one of your crew is in the water! How would many of us react? Sure we’ve taken courses, maybe even practised in light air. How many of us fully realise the seriousness of a COB? Or worse feel like "it’s never going to happen to me, I only sail in fair weather, I’m always careful," and so on...

My intent with this article is not to teach procedures but to take sailors who already understand the basics of crew overboard recovery one step further. We all need to keep in mind the possibility, no matter how remote, that this can happen to any one of us and that when prevention fails readiness is our best defence. By this I refer specifically to practice and contingency planning. Thinking about what we’ve learned and how well we understand the procedures we were taught and also coming up with some "what if’s" that are rarely given thought. For example: " Would that heaving line hanging from the pushpit fly or would it end up as a polypropylene bird’s nest at our feet?" or "What if the auto pilot is engaged when someone falls over?"

As a cruising instructor I have taught COB procedures many times and it has come to my attention that there are a few general points that should be further discussed. First, if we practice at all after our course, it is almost always in fair conditions. While I believe that these conditions are required to effectively teach and begin to practice the manoeuvre, chances are that a COB will occur in less than ideal conditions. It is human nature to want to avoid difficult or uncomfortable situations and ironically they remain that way through lack of practice. In the case of the COB manoeuvre we are almost never forced to practice, with potentially dire consequences should we ever need to use it. Reviewing the procedure in a book then trying it is not easy. One way to bridge this gap is to use models and practice the procedure with a bird's eye view. Plasticine, available at the local toystore is ideal for this purpose. Working through the steps in a controlled environment helps the student put them together more easily. For the skipper and crew who have not practiced in a while this is a good way to get back into it. Then go out and practice, in moderate conditions at first but not ignoring the obvious benefits of practice in heavier weather.

Under sail I feel that the triangle method is the most effective because it will work best in all conditions. There are a few points however that may not be fully understood and are crucial to the success of the manoeuvre. There are two common problems experienced by students when learning and practicing this procedure. The first is not going to a beam reach as soon as the alarm is sounded. This happens because the skipper is under sudden pressure and may be confused by so many things to think of at once. The purpose of immediately getting the boat on to a beam reach is for the skipper to "get organized" and go through the steps of spotter, ring, pole,...etc. Four to six boat lengths used to be the rule before the skipper would head up and tack. This is no longer the case. Take only the time needed to get organized. This "organization" phase helps to ensure success on one pass and reduces the chance of a series of panicked and missed attempts. The second problem stems from an instinctive desire for the skipper to head straight back to the COB as soon as the boat has come about. The aim is to arrive at the COB in control, stopped alongside to leeward. If the boat returns directly to the COB it is generally on a beam reach and making good speed. It is impossible to stop by heading up at the last minute and the boat will usually overshoot the MOB. By bearing away to a broad reach and then heading up to a close reach when the MOB is abeam of the bow the boat is brought back to the MOB under control using mainsail only to control speed.

Does the use of power have its place when returning to a COB? What do we do when motoring in heavy weather in a power boat or a sailboat with no sail up? The method for returning to a COB while under power is called the Williamson Turn. As soon as the alarm is raised the boat is turned 60 degrees to the side over which the crew member has fallen. The boat is then brought back around in the opposite direction and on to the reciprocal course, the engines are stopped(put into neutral) and the vessel should drift to the COB’s position. There may be no choice but to return under power to the person who has fallen over while motoring, but extreme care must be taken as the propeller increases the risk of injury to the COB. Some skippers while under sail may be tempted to return under power. Trying to lower sails and motor back, especially in heavy weather, further endangers the COB and remaining crew members, it also presents the risk of fouling the propellor with lines.

Finally, I want to touch on the difficulties of recovering a COB. How many skippers and crew have tried to bring an unconscious or injured victim back on deck? There are many accepted methods, all having their own advantages and disadvantages. Think simple to complex, get the COB to help themselves as much as possible. Keep in mind that rescuers often join victims as double statistics. It may be a simple matter of throwing them a heaving line then recovering them through an open transom. If the COB is injured or unconscious the degree of difficulty and danger to rescuers grows significantly. The point I want to make is that we need to think seriously about how we would get that crew member back on the boat and then consider experimenting with different methods under safe and controlled circumstances.

Thankfully the incidents involving crew members falling overboard are rare but they do happen and we cannot hide from that fact and simply hope that it won’t happen to us. This article has touched on only a few "what if’s". The prudent skipper and crew will be able to come up with more. Many things can be done to prevent such an event but if we fail in this regard and are suddenly faced with this situation we need to be ready. Looking at the big picture, contingency planning and practice will all go a long way to ensure that we are better prepared for that unwelcome, chilling cry.'

The short video above shows a practice run with buoy and there is another sixteen minute production you can view with a real live MOB at 'Open Film'.

Marco's article gives sound advice and worth practicing in a varied range of weather conditions. For retrieval of a MOB I rigged up a simple device which worked effectively in practice. It consisted of a double block at the upper end with snap shackle to hook into the saddle under the boom. At the lower and business end I used a single block with fiddle (for ease of use in the hand), also with a snap shackle. The boom was about eight feet above the water so I ran fifty feet of line through the assembly.

Swinging the boom out over the water it was easy to drop the fiddle block end to a MOB in the water to clip on to their harness. This combination of blocks can easily lift a 100kg wet MOB. If they were unable to help themselves then a crewmember could reach through the guidelines and clip it on as the boat rolled. If the MOB was wearing no harness, then out came the LifeSling to get under the MOB arms and hook on to the snap shackle of the block and tackle unit. It is easy to hoist the MOB up and then swing the boom inboard. I fashioned a sturdy plastic container and fastened it above the clutter to the outside wall of a cockpit side pocket. All crew knew where it was for instant accessibility. Fortunately, it was only used in drills.

Article courtesy Marco Coda and Lands End Sailing School.

You can read more about safety at sea methods whilst on passage in my ebook 'Voyage of the Little Ship Tere Moana' downloadable from my website for sailors

And finally, I would like to welcome you to our new look and updated blog. I thought it was time to freshen it up a little and I trust that you approve. Feel free to make a comment and post it in the 'make a comment' box.

Sunday 12 September 2010

Broadband Radar for Sailboats

Broadband radar for sailboats has come a long way in a very short time. It has so many advantages with so little downside that it has to be the radar of choice for all cruisers whether it be a new installation or a replacement for your old tired unit. Apart from the clarity, sharpness and integrity of the image, the marked drop in power useage and instant 'power up' are two other major features of interest to cruisers. Take a look at the image here for a comparison with the earlier pulse systems and Broadband and also the video to see the difference for yourself.

The following article is from 'FishingGear Guru' a website devoted to better fishing:

'Forget about bang suppression, the necessary radar programming that causes that ring up to 100’ around the boat, which shows up as solid on-screen. New Broadband technology fromNavico (parent company to Lowrance, Simrad, Northstar, and others) eliminates the big bang, offering visibility and awesome target discrimination mere feet from the radome. Plus, small boats that couldn’t support the weight and power consumption a radome requires can now see through the fog and the darkness. This system is a game-changer, making it possible to install a dome on virtually any boat large enough to support a T-top or arch.

The dome is a mere 11” tall, 19” around, and weighs just 16-pounds. How can this unit be so light, small, energy efficient, and yet still see up to 24 miles into the distance? Traditional radars send out a microwave pulse, then measure the amount of time it takes for that pulse to be reflected by a target. In doing so, they pull enough juice to drain a single marine battery in a matter of hours. On top of that, they radiate a significant amount of energy and when installed in an improper location, may zap you or your passengers with microwave radiation. But Navico’s new Broadband radar sends out a continuous transmission wave with a 5.2-degree horizontal beam width, which increases in frequency as it moves away from the dome. The difference between frequency in the transmitted and returned wave is how the unit determines target distance. That means this system uses less energy to make radiation-free transmissions, eliminating the power concerns you’d have on a radar-equipped boat with a single battery and close proximity to the dome. Though I had no way to check it for myself, Navico claims the power transmission is a mere 1/2000th as much as traditional radar, which is about a tenth of the power a cell phone uses.

What I could check out for myself was the result of using frequency instead of time reflection, when I jumped aboard Navico’s broadband-equipped test boat at the Miami boat show. Target definition in the shorter ranges is phenomenal, good enough to see the difference between piers and the boats moored at them. In fact – I am NOT making this up – we could see two gulls sitting on the water about 30’ from the boat, on-screen. And that “dead zone” of blank space around the boat is completely eliminated with this system, so you can get returns on boats, land, and other structures just feet away from your own boat. We approached a pole and when the bow of the boat was so close someone had to fend off, the pole still showed on the radar. A sailboat just 50’ away—in the bang zone of regular radar—showed up on-screen clear as day; one of these pictures shows the screen shot at the moment, and the other, of the sailboat providing the return in the lower right corner. Even on longer ranges up to 10 miles or so, you can expect target resolution in the two to three meter range. Plus, the antenna uses all solid-state parts, which means there’s no warm-up time—just flip a switch, and the unit’s up and running.

Put all of these factors together, and you have a unit that can be easily mounted and run on a platform far smaller than any that could accommodate a radar prior to Broadband. Big boats will want it too, for close-use when the fog’s thick…and the blind zone created by bang suppression could cause you to bang into something in your way.'

Article courtesy Lenny Rudow of FishingGearGuru

You can read more about incidents with radar and shipping whilst on passage in my ebook 'Voyage of the Little Ship Tere Moana' downloadable from my website