Boat Handling Tips on travelling at speed.
The reason most of us have a nice powerful powerboat is so that we
can travel at nice high speeds while the rest of the world is trundling
along at an altogether more sedate pace.
While bombing around at high
speed might seem simple enough, there is a definite set of skills which
go with it in order to get the maximum out of your boat in the safest
and most comfortable manner.
One person who knows more
than most about this is the RYA’s Chief Instructor for Motor Cruising
and Power, Rachel Andrews. Rachel has been speeding around in all kinds
of powerboats for over a decade now, so she’s in a good position to give
She explained: “Travelling at speed is
great fun, but if you don’t handle your boat correctly and make sure it
is trimmed right, then it can become uncomfortable or even dangerous.
The complexities of advanced powerboat handling can best be learnt
through the RYA Advanced Powerboat Course, but if you’re waiting for the
weather to warm up, these tips from the RYA Powerboat Handbook will
- If your vessel is fitted with a kill cord, make
sure you wear it at all times.
- At speed ensure that your crew have a
good seating position, a firm grip, and know what you are going to do
before you do it. They can only know what you are going to do if you
tell them beforehand.
- Avoid situations which involve
rapid changes in direction. Take early action in potential collision
situations and remember if in doubt, take the power off reducing the
closing speeds of vessels.
- Keep a good look out for other craft, keep a
watch for and predict the effect of waves or the wash from other
vessels. By keeping alert and assessing situations early, you can make
high speed driving safe and fun.
- Most importantly, adjust your speed to
suit the conditions, traffic and environment in which you are
Travelling at high speed
It takes a lot of power to get on the plane. Once there it may be
necessary to throttle back slightly to ease speed and conserve fuel. A
displacement or semi displacement hull will never achieve the ability to
plane on the top of the water so its speed will be governed by hull
form and the power available.
Before accelerating ensure that the engine is either fully ‘trimmed
in’ or to the neutral position depending on the craft. This helps the
boat get up on to the plane.
As the throttle is pushed
forward a powerboat begins to move from being a displacement boat at low
speed and starts to climb on top of her bow wave and get on the plane.
As speed increases, less of the boat is touching the
water. This reduces friction allowing speed to be maintained with less
High speed turns
Whenever turning at speed it is important to warn the crew so that
they are not thrown out of the boat. Turning too sharply allows the prop
to suck in air (ventilate) and lose grip on the water. Slowing the rate
of turn or the amount of revs will allow the prop to grip again. Trim
down before commencing a turn for greater grip and control during the
Turns through 180°
When approaching a turn; set up the boat by
trimming-in the leg, take off some speed, look around especially
behind, warn your crew, then execute a wide turn keeping the boat on the
plane by managing the throttle. If you turn too tightly most of the
speed will be lost. Coming out of the turn apply power and trim-out.
(gradual turns to the right or left) can be made at reasonably high
speed as long as they are steady and controlled, when the conditions are
suitable. Again use all round vision and communicate your intentions to
In turns some stepped
hull designs can behave less predictably than ‘standard’ hulls and care
should be taken to not trim in too far and to not reduce power suddenly
in the turn. Consult the Owner’s Manual and dealer for detailed
instructions relating to your type of craft.
Trimming your boat
explains the concept of boat trim: “At different speeds, your boat
needs to be trimmed in different ways, both to get the maximum speed out
of your boat and also the most comfortable ride.
can trim your boat in two ways; fore and aft – raising and lowering the
bow, and from side to side levelling the boat if it is leaning to one
side. Don’t forget that where you position people and kit in the boat
will also affect the trim of the boat.”
Leg in to start to keep the prop in the water and help the boat get on the plane.
the plane ease the leg out to achieve the best speed. Ease out too much
and the prop sucks in air from the surface, making it spin faster but
lose grip on the water, therefore slowing the boat. Ease the leg out by
the correct amount and the revs increase slightly without the throttle
being adjusted, therefore speed increases.
If the boat
starts to porpoise (the bow bounces up and down), trim the leg in to
regain control, and then slowly ease out to re-trim.
needs constant adjustment. If crew move around the boat or there is a
change in sea conditions or speed, you need to check the trim. Fuel use
makes the boat lighter – you may need to trim differently when tanks are
full or half empty.
Rachel’s top tip: “Even when trim gauges are fitted, they can be
unreliable. Practise in various conditions to get the best trim. When
there are no gauges, use time increments to know whether the leg is up,
down or centred. While in port count how long the tabs take to rise,
lower and centre. When trimmed correctly the revs rise slightly and the
helm feels lighter without pull to either side.”
Trim tabs are either flat plates or vertical blades
fitted either side of the boat and attached to the transom. They are
used to trim or level the boat, both fore and aft and side to side. Trim
tabs are controlled up and downwards by either a hydraulic or electric
ram system on the transom.
- Tabs down – raises the stern which in turn depresses the bow (bow down)
- Tabs up – lowers the stern which in turn raises the bow (bow up)
- Tabs can also be used to compensate for a beam sea or uneven loading
Tabs can be helpful when getting up on the plane. Tab down to lift
the stern. Tabs should not be needed, but may help compensate for the
crew standing at the rear or weed on the hull.
tabs are mainly used at speed, they can also be used tabbed down in
marinas to increase grip on the water. Beware of powerful reversing when
tabbed down, as this can cause damage to the tabs.
can make a huge difference to comfort and sea-keeping ability at speed.
It is possible to achieve basic steering using one tab at a time.
in different conditions will give the best compromise of comfort, fuel
consumption and ride, but tab half down is a good starting point.
Rachel’s top tip: “If you have trim tabs and the ability to trim the
drive leg then try to keep it simple. Use power trim for fore and aft
trim and trim tabs for side to side trim.”
Hopefully these tips will translate easily when you get out on to
the water, but for practical training, why not sign up for the RYA
Advanced Powerboat course.
These pointers were taken from the RYA
Powerboat Handbook, written by Paul Glatzel, if you would like to read
more, pick up a copy by going to the RYA Website.
More information on Boat Handling
Find books for your course at the RYA Shop
Our handy guide shows the books & DVDs that go with your course!