Ask the RYA Experts: Boat Handling - In Difficult Conditions


Boat Handling - In Difficult Conditions


It is vital of course to obtain a marine weather forecast before departure, however sooner or later you're bound to face conditions that will test your skill and nerve. An increase in wind strength or sudden change in direction can transform a tranquil trip into a rollercoaster ride.

With experience, skill and the right boat, heavy conditions can be thoroughly exhilarating. But without the right technique, it can be unnerving and even potentially dangerous. Recent research has shown that crew seated in a powerboat can experience forces as high as 14G – not appreciated by your spine!

So, good technique is all important, and these tips from Paul Glatzel's RYA Powerboat Handbook are an excellent starting point.

Paul explains: "In rough conditions, match your speed and course to the conditions, with careful control of the throttles and steering. Jumping from wave to wave or ploughing through waves can be great fun, but you, your crew and the boat will find it very wearing. Make sure that everyone has good handholds and seating positions and the helmsman is wearing the kill-cord."

Driving upwind

Waves are generated by wind and generally come from the same direction. Driving into the wind therefore means driving into the waves. Driving downwind, the boat drives with the waves. Applying correct technique will ensure safety and comfort.

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Driving upwind entails trimming down and
driving up the face of the wave.






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Ease off at the top of the wave to ensure you do not take off.






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Accelerate down the back of the wave, speeding up to raise the bow as the trough is reached, then drive up the next wave towards the next crest.





The ride then becomes relatively smooth and quite No_55__Converted_fast. Progression is achieved by throttling on and off as you move over each wave. Trimming down ensures that the 'V' of the hull is used to slice into the approaching wave, while applying more throttle lifts the bow in the trough to drive up the approaching wave and prevent the bow driving straight into it.

This avoids the need for trimming up and down to achieve the same effect.

Tip - Upwind - This can be summed up as: when the bow is rising - throttle on, when the bow is falling - throttle off. Whether this proves to be a comfortable ride or not depends to a large extent on the 'wavelength' (the distance between the wave crests).

Short steep seas make it very difficult, as there is little time between wave crests for the helmsman to adjust the throttle settings.

In this case, you may find it easier to drive at 30º–45º to the wave front. This increases the 'apparent wavelength' and can therefore allow you to increase your speed and smooth your journey.

You will then need to zigzag towards your destination but, while longer in distance, this method can be less stressful and quicker.

Beam seas

Large breaking waves taken on the beam have the potential to capsize a boat. Keep a fair speed up and constantly watch for breaking waves. Steer a path behind, or in front of and away from them - as conditions dictate.

The speed and power of your boat is key. If you get caught on the downwind side of a breaking wave, turn into the wave and power on to climb up the wave, or alternatively turn away from the wave and outrun it.

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Driving downwind

One of the most dangerous conditions for any boat is a 'following sea'. If a breaking wave catches the vessel, the aerated confused water catches the prop, reducing its ability to bite.

The following wave may then turn the craft side-on to the waves making capsize almost inevitable with the next wave. To avoid this, be sure to match the boat's speed to that of the waves.

Another problem of going down the face of a wave is going too fast through the wave, causing the bow to fall into the trough (and plough into the back of the next wave). Then as the boat loses speed, the next wave pivots the boat beam-on and either swamps or capsizes the boat.

To make progress in these conditions, trim the bow up and ride the wave, staying behind the crest.

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As it breaks, care is needed not to power through the breaking wave too early. As the wave breaks, you may need to ease the power in the confused water to avoid the prop losing grip.



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A good look out astern must be kept at all times to avoid chasing waves catching you up. Alternatively, pick a calm patch to turn into the breaking sea and look for another destination.



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Watch your boat speed as you may need to ease the throttle, then power through to sit on the back of the next wave.





The conditions you experience may be magnified or reduced by the combination of wind, tidal stream and depth of water.

Wind blowing in the opposite direction to the tide ('wind against tide') will create short, sharp, unpleasant seas. Tide flowing in the same direction as the wind will have a smoothing effect.


Conclusions

Competent handling in rough conditions can make the difference between, a stressful, potentially dangerous experience and an exciting, enjoyable trip. Hopefully these tips will help you to get the most out of your powerboating.

Two "golden rules" drummed-in on all RYA Powerboat courses are:
  • Always wear the kill-cord
  • Always maintain three points of contact (one hand on the throttle, one hand on the wheel, and your butt on the seat)

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Excerpts taken from "RYA Powerboat Handbook" ($54.90) by Paul Glatzel, available from Trans Pacific Marine 0800 422 427 sales@transpacific.co.nz

Practical boating courses are available from RYA Training Centres throughout New Zealand, administered by Coastguard Boating Education: Contact 0800 40 80 90 or www.cbes.org.nz



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