200205 Are the Collision Regulations so difficult to Understand?

Are the Collision Regulations so difficult to Understand?
Report No. 200205

On a particularly quiet day in the South China Sea (i.e. no fishing boats around!) I was overtaking a general cargo vessel, giving her a CPA of approximately 2 miles. Both vessels were making good a course of 206 true. As I was approaching the general cargo vessels starboard quarter, a small coastal tanker was observed crossing from port to starboard on an approximate course of 300 true. I overheard the give way vessel (tanker) call the general cargo vessel on VHF and ask her intentions???

The general cargo vessel replied, stating that the coastal tanker was going to pass ahead at just under 1nm and the intention was to "stand on". This was understandable, as she was the "stand on" vessel and the tanker was the "give way" vessel. By now the coastal tanker was giving me a CPA of 0.0nm at 18 minutes crossing from port to starboard in a clear crossing situation. The coastal tanker then proceeded to call my vessel giving the usual 'ship on my starboard side' I knew that the OOW was trying to call my vessel, by giving a very vague description.

I saw the tanker cross the general cargo vessel's bow, "standing on" and now showing a CPA of 0.1nm at 10 minutes. The Captain arrived on the bridge for a coffee and I informed him of the situation. Once the tanker was 1.5nm on my port bow, 5 short and rapid blasts were sounded on the forward whistle. At a range of 1 mile on my port bow there was no change in bearing of the approaching vessel. The helm was put hard to starboard and 1 short blast sounded on the forward whistle. As the vessel passed our stern at 2 cables the Captain called the tanker on VHF stating the vessel's name and position and asked the tanker's reason for not giving way. The response I was shocked to hear was, and I quote 'I tried to call your vessel but got no reply so I no change my course'. Are the collision regulations so difficult to understand??