A German company sells you a used boat from a third country (e.g. USA). The German company will only act as a broker, but will take over the organization of the transport as well as the customs clearance and the payment of the import sales tax on your behalf. In this case you should note the following:
The purchase contract is concluded between you and the foreign company. The German company acts only as a broker and forwards the purchase price (less a commission) to the foreign company.
An inspection of the boat is only possible abroad.
In this case, you personally are considered the EU importer. Usually, used boats that you buy from a dealer in the USA or in another country outside the EU do not have the necessary EU conformity. As an EU importer, you are responsible for ensuring that the boat complies with the 10th Regulation of the Equipment and Product Safety Act (GPSG) before it is put into service for the first time within the EU. For this purpose, you must involve an accredited certification company (Notified Body). The boat must be inspected and subjected to a "Post Construction Assessment". If necessary, modifications must be made to the boat. This mandatory procedure involves not inconsiderable costs. The technical documentation required for the assessment must be provided by you. In addition, you are obligated to prepare the "Handbook for Boat Masters" or have it prepared.
You have possible warranty claims against the foreign company. If necessary, claims must be enforced in court abroad.