U thought this most recent post from gcaptain was worth repeating:
"Kennebec_Captain
Is it safe to assume that a ship's captain might use the light instead of the VHF in order to avoid embarrassing the other vessel's captain by broadcasting over the VHF, a channel open to all in receiving range, and also something that would be recorded on those vessels' VDR's?
Is is also safe to assume that another case in which a ship's captain might use the light instead of VHF to signal a ship at night who isn't transmitting AIS, since they would not know who to hail on the radio? "Hello, ship near Japan, have you got yer ears on? Breaker breaker good buddy, & all that." It occurs to me that trying to hail a random ship out of maybe fifty ships which might receive the transmission might get either no response, or many responses.
The light was used more often pre-AIS because of the time and trouble it took to communicate. Not to mention the risk of making passing arraignments with the wrong ship. Now with AIS the VHF is more often the go to tool to sort out complex traffic situations with another ships, for example two ships approach each other while weaving through a fishing fleet.
With fishing boats without AIS it likely not worth the time to try and contact via VHF. Say I'm meeting a large vessel port to port and overtaking a fishing vessel to stbd, with bad water to stbd, the F/V starts to creep in on me a quick flash of the light "hey I'm here" most often does the trick. Unlike the 5 short blasts the light is specific to a single vessel.
Under stress people tend to revert to old habits, if the crew used the light frequently but not the whistle that might explain that reaction, of course they "should have" used the whistle as well.
27182:
Y'all attract a lot of attention when a big news event happens and your industry might benefit by adding some additional context for the broader than normal audience.
Yes, that's true, but most people don't read long posts, I sail foreign deep-sea, world wide. Taiwan Strait, Korean Strait, South China Sea, Japan Sea, Singapore Strait, Gulf of Thailand all involve encountering heavy, mixed fishing boat / large ship traffic, a little more to it than saying follow COLREGS."