In 1980 HFL started manufacturing a range of generators based on the VW Golf diesel, producing a series of compact marine diesel generators capable of 25KVA output and weighing just 400kg. These generators attracted the attention of famous designers, as a result HFL generators variety of famous jachts and motor-boats.

 HFL received orders for two generators along with instructions that one was to be delivered to the USA and the other to Spain, with no mention made of the end user. They were promptly shipped and there was nothing further said, until, that is, HFL Managing Director Horst Lentge heard an announcement over the

campsite tanoy system whilst on holiday one summer in Port Grimaud, south of France. The announcer asked Horst to come to the office, where he was given an urgent message to speak to Richard Cross, Captain of "Fortuna", a new motor yacht owned by King Juan Carlos, the King of Spain. To Horst's surprise he discovered the whereabouts of two generators, they were both on Fortuna, by lucky coincidence close by to Port Grimaud. Richard Cross then explained he was having problems with the generators and that it was crucial for the generators to be working, as a certain Prince Charles was due to be on board imminently, along with his new wife Diana, Princess of Wales, for a holiday.

The problems had been caused by modifications made to the control and damping systems during the generators visit to the USA., compounded by the fact that Fortuna was a high performance boat and the generators being thrown about due to the effects of the oversoft mounts retrofitted. The problems were resolved and the boat sailed away, with all on board set to enjoy a happy holiday.

Later during the year, HFL and other suppliers were invited to Spain to discuss the problems experienced on Fortuna. The King's representatives, quite naturally, expressed the King's need for the boat systems to be reliable, and when discussions finally came around to the generators, Horst was well aware of the particular operating conditions and requirements. It was subsequently agreed that HFL would develop and build two new 50KVA high speed diesel generators based on the VW six cylinder engine. While the King's representatives were sceptical, Richard Cross was enthusiastic and his support led to a positive decision.

Whilst on board Fortuna, HFL also noticed that the airconditioning system was not functioning correctly. It was agreed that the original equipment would be removed and would be replaced by HFL with a more efficient system. The new generators and airconditioning system, supplied in March 1982, were an overwhelming success, operating for a period of nine reliable years before the replacement of the generators in 1991 with two HFL Ranger 65KVA's.

This entire business happened at a time when HFL was just beginning to succeed as a Company, and the resulting confidence gained from a satisfactory conclusion to Fortuna's problems enabled Horst Lentge to go about business with a new confidence and assuredness, safe in the knowledge that HFL was now, officially, "fit for a king".