Raymarine ST40 - Manual (Page 21)

12 ST40 Speed Instrument Owner’s Handbook
The transducer should:
• Be ahead of the propellers (by a minimum of 10% of the water line
length ).
• Be at least 150 mm (6 in) away from the keel (ideally ahead of the
keel if a sailing yacht).
• Be as near as possible to the centre line of the vessel.
• Be clear of other through-hull fittings or projections.
• Have sufficient clearance inside the hull to fit the nut.
• Have 100 mm (4 in) of headroom to allow for withdrawal.
The transducer should be sited within the clear water flow areas
indicated by the shaded areas in the following diagram.
Sailing vessel
Planing power
vessel
Displacement power
vessel
Transducer siting
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