Split and simplify the following sentence while retaining its full meaning: Whereas the definitions decided upon should reflect as much as possible the definitions of vessel characteristics at present applied in the Member States; whereas Community action in this field should therefore be based upon initiatives already taken by specialist international organizations.
 Simplified version:
The definitions chosen should correspond as closely as possible to the definitions of ship specifications currently used in the Member States . Community action in this area should therefore be based on initiatives that have already been taken by specialized international agencies .