It's understandable, but I had to read it two or three times. It could be read as only the planning took place on board, and that the visit itself might take place anywhere. I think this would benefit from reordering, such as:
1. If a visit on board a vessel from Owners' representatives, co-operators or guests is planned, the Master of a floating vessel should inform the Ship Repair/Building Manager or Project Manager of such a plan in advance in order to make their entrance procedure easier.
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