Why do I need a Thruster?
A Thruster makes boat handling, especially in tight harbours, much
eaiser by gently moving the Bow with a small independently driven prop
without having to use the main engine.
I am buying a new boat but havenít decided to have a Thruster
installed can it be fitted later?
Yes, there are plenty of installers around. It may cost a little
extra and will involve hauling the boat and a few days of installation.
What Battery power do I need?
Thrusters have very powerful electric motors and it is recommended
where possible to have a dedicated Battery close to the Thruster with a
separate charger. This saves the problems of installing expensive, large
cables from the main battery bank.
Can I install the Thruster myself?
The majority of the work involves choosing the location and
installing the tunnel. A suitably qualified person should always carry
out this work.
Can a Lewmar Thruster replace my existing installation/ I have a
tunnel and standard fit by another manufacturer?
Yes in most cases providing the tunnel has the same internal
Choosing the right Lewmar thruster for your boat.
Today most yachts or motorboats over 45 feet have a bow thruster fitted as
standard. The thruster will usually meet the expectations of most customers when
using the boat under normal weather conditions. The sizes used by boat builders
will vary depending on the boat's intended usage and price level. In today's
production boat's of around 45-50, the typical thruster will push the boats bow
against a direct side wind of 20-22 knots.
For boat owners who use their boats in more demanding conditions or have a
strong current in their local marina, Lewmar can offer upgrades to a higher
performance thruster. However, few pleasure craft need a thruster that can push
the bow against a direct side wind of more than 25 knots.
The boat's wind area, the lateral wind draft area and the thruster's tunnel
position in the hull determine the thruster's performance on a boat. By knowing
these factors we can calculate the wind pressure on the boat and the centre
point of this wind pressure. However the wind pressure is seldom from right
angles and many boat superstructures are quite streamlined so we can reduce the
factor slightly. From these calculations we can determine what thrust is needed
to counter the wind pressure with the given thruster position.
To gain total control of your boat in combination with a bow thruster the
solution is to install a stern thruster leaving the main engines to propel the boat forward and backward
as they were intended