Placement Guide for Spray Control
To gain the maximum effectiveness of
THE SMART-RAIL®, it is
important to determine the type of hull and the speed at which you want to
get the maximum effectiveness. Some customers use both models, M-1000 and
M-2000, at different levels for low and high speed spray control.
- Planing Hulls at Planing Speeds - With hard CHINE (where side
and bottom of hull meet). Place M-2000 Rail on the CHINE, starting 1" to
2" from the STEM (where the two sides of the bow meet).
- Planing Hulls at Speeds Below Planing - In a heavy sea, the
wave may strike the bow above the CHINE. Place M-1000 Rail just below the
- Displacement Hulls at Cruising Speed - On sharp entry bows, the
M-1000 is placed at a point just above the bow wave. On blunt entry bows,
the M-100 is placed substantially above the bow wave.
NOTE: The principle here is to place the rail in an area of the bow where
the wave thickness is not more than the width of the rail. Determine the
source area from which the spray originates at trolling speed through to top
speed in the following sea conditions:
- Trolling speed in head and quartering rough seas?
- At medium speed in head and quartering rough seas?
- At high speed in head and quartering rough seas?
It is helpful to view or photograph the boat in all sea and heading
Looking over the bow can also help in determining the appropriate
position of the rails. Follow all common sense and safety precautions, i.e.,
safety harness, padding and communication with a competent captain at the
helm. Hand signals can be helpful in raising or lowering the boat's speed.
CAUTION: When the boat's bow impacts a big wave at speed, there will be a
substantial jarring force, so start your test at low speed to determine your
NOTE: Many boats have a "disappearing" chine for 2 or 3 feet from the
THE SMART-RAIL® is flexible
(you may use a hair dryer) so the rail can be adjusted to the changing angle
of the chine. For best spray control, the length should be equal to at least
1/3 the length of the water line.
Following this study will allow you to make the appropriate choice of
rail location. HAPPY BOATING!
should be installed one third (1/3) the
length of the boat starting at the stern running forwards.
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