We were 10 miles offshore in the North Sea in Venture II when a very smart Dutch Kustwacht (Coastguard) launch showed up and looked us over.
They asked us to reduce speed to 6 knots and held station a short distance away before lowering a black rib which sped towards us over the choppy seas with four men on board. They came alongside and two of them boarded through the side gate while the other two remained in the rib and stayed a couple of hundred yards away. Of the two who came aboard, one was armed with a side arm. They were very professional, shook hands with everyone, and removed their wet weather gear, boots and side arm before entering the salon. They said they had come about our violation of the rules concerning the inshore route the previous day and had print outs of our route to prove it! The inshore route is restricted to vessels 20 meters or less. We explained that we were just under 20 meters and showed them the registration certificate confirming the length at 19.8 meters. They said that the shoreside station which had reported us had told them that, according to our AIS, our the length was 25 meters.
After examining our documentation they conceded that we had not in fact violated the traffic rules but we had better get our AIS checked. After twenty minutes on board they departed with handshakes all round and best wishes for success at the Hamburg and Dusseldorf shows to which we were on our way.
No one likes being boarded but these people were 100% professional and very businesslike. They were polite but clearly well prepared and experienced. They had a job to do and did it very professionally so we were left with feelings of admiration rather than irritation. After the encounter I requested permission to use my video camera which was granted.
The episode described starts at 4 minutes 7 seconds into the video.