Both the Coast Guard and the NTSB have now released their reports on the sinking of the Alaska Ranger. The Coast Guard's report can be found at the CG site Homeport - type "Alaska Ranger" into the search box to find the report. The NTSB's report can be found here.
The Alaska Ranger case is not complex. The hull of the vessel was in such poor condition that, in typical Bering Sea conditions, water entered and flooded the entire vessel. The actual point of failure evidently was the Kort nozzles which were tacked onto the vessel in 1991.
The Coast Guard report claims that there was ambiguity in regulations regarding the Ranger status as a fishing vessel or a processor. Thirty-two of the forty-nine people aboard the Ranger were titled "Factory Processors", that makes it a processor.
The Coast Guard created a loophole in the law called the Alternate Compliance Program which according to the Coast Guard
"allows exemptions to the class and Load Line requirements while at the same time creating improved safety requirements for these vessels, thereby avoiding the incentive to operate strictly as uninspected fishing vessels. ACSA vessel owners work with the Coast Guard"In effect the Coast Guard put it's stamp of approval on a vessel which was not seaworthy but which carried thirty non-mariners onto the 32 degree waters of the Bering Sea.
This is a case of risk assessment, scrapping the Alaska Ranger would have risked adversely impacting the owner's bottom line.
My previous post Alaska Ranger - shitty job, shitty boat is here
From Jones Act Blog - Coast Guard Releases Investigation Report on ALASKA RANGER Sinking
What Sank the Alaska Ranger? A Perfect Storm of Mechanical Malfunctions and Human Missteps - Kalee Thompson, Author of Deaadliest Sea
Alaska Ranger - Wikipedia Article
Alaska Ranger: Lessons from Coast Guard’s most challenging rescue - Kalee Thompson post at The Coast Guard Compass