Raymarine ALPHA Installation Instructions Manual page 36

Warning: Collision avoidance
In order to avoid potential physical damage to the unit,
ensure that the environment surrounding the unit is clear from
potential objects that may cause collisions.
Warning: Marine-grade sealant
Only use marine-grade neutral cure polyurethane sealants.
Do NOT use sealants containing acetate or silicone, which can
cause damage to plastic parts.
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