Hr Ms Soemba at Den Oever Harbor in The Netherlands.  The ship was used for Navy diver education until the second half of the 1980's. The ship has a fantastic history: it was in service on D-Day on the shores of Normandy.

March 1966. Start of second class diver training!
Out of 26 sailors, only 8 passed the final exam.

April 1966. The first mixed gas dive in Siebe Gorman/Davis "Salvus" diving equipment. The system was completely built around the diver. It featured a drysuit in two parts and a rubber helmet with exhaust valve on top. The frontglass hinged down. Two 2 liter cylinders on the back with reducing valve and bypass. On the chest, the counter lung with CO2 scrubber. 
In 1966, this system was already outdated. 

After he finished second class diver training, Henk stayed in Den Oever as a carpenter on the Soemba. In august 1968 he started first class diver training with three mates. This course focussed on standard diving. Close to the end of the training, in november 1968 Henk was involved in a serious diving accident. One of his mates was brought up unconscious from a depth of 30 meters after a dive with a rebreather system. He turned out to be OK and suffered no serious injury. However, he was rejected from any further diving activities and so was the rebreather system! The other two colleagues stopped training as well. Henk was the only one to pass the exam. At a later date, the two mates took the course again and finally ended up high in Navy diving ranks.

Standard diver training. These pictures were taken in June 1966. In both cases, Siebe Gorman 6 bolt helmets are used. Especially for the Navy, a top light was mounted. 
Also, the nipples were replaced with eyepads to mount the hooks on the weights. 
In the left picture you can see an extra air inlet on the breastplate. 
These helmets were sometimes used with Loosco or Dräger air chest weights. 
The helmet on the left also has a large and unusual communication box mounted on the right front side.

Some of the crew members posing with the ARGUS. The last diving vessel Henk was assigned to.

After leaving the Navy, Henk returned to Terschelling. A few years later, in 1975,  he started teaching SCUBA diving. This turned out to be a great success and in 1976, Diveteam EQUADOR was born. In his Navy time, Henk only went down in the Waddenzee and the IJsselmeer. Two environments with terrible visibility. Now, in Terschelling harbor, the visibility was sometimes 4 meters but on wrecks in the North Sea, it could be up to 12 meters! He still is an enthusiastic wreck diver today.