Stephen Humphreys was the skipper of the Flying Phantom, which sank in fog on the River Clyde on December 19, 2007.
The 33-year-old, from Greenock, died along with Robert Cameron, 65, from Houston, Renfrewshire, and Eric Blackley, 57, from Gourock in Inverclyde.
Another crew member, Brian Aitchison, 37, was rescued.
Widows have previously called for a FAI to be held into the deaths but such an investigation has not yet taken place.
Now, on the fifth anniversary of the men's deaths, Helen Humphreys said: "My own experience of the current system of investigation of workplace fatalities, since the death of Stephen, has allowed me to see first-hand the deficiencies in the process. In particular, I have experienced frustration at the length of time taken with no resolution in sight and I have been left feeling a lot of anger at the lack of respect for Stephen's life and the feelings of his family."
She spoke out as Labour MSP Patricia Ferguson announced plans to introduce a Member's Bill to Holyrood to try to reform the system for FAIs.
The parents of Army cadet Kaylee McIntosh, who died age 14 after being pinned under a boat on a training exercise on Loch Uist, in 2007, has also condemned the FAI system as out-of-date, alienating and infuriating since none of the inquiry's recommendations have been acted upon. Lesley McIntosh, Kaylee's mother, said: "The system must be brought into the 21st century."
Ms Ferguson is seeking to change the Fatal Accidents and Sudden Deaths Inquiries (Scotland) Act of 1976. She said her experience of working with the families of those killed in the Stockline explosion in Glasgow had left her "all to aware how anachronistic the current FAI system is".
A review of the system carried out by Lord Cullen seems to have been a wasted opportunity she said, with its proposals "yet to even be implemented".
Ms Ferguson said: "I am bringing forward a bill which I hope will garner widespread support from a majority within the Scottish Parliament."
A public consultation on the bill is to take place next year.
The union which represented the Flying Phantom crew has already welcomed Ms Ferguson's plans. Unite Scottish secretary Pat Rafferty said: "Time and time again we have been shocked by disasters such as the Flying Phantom and then angered by a system which has no defined structure to prevent a repeat of such an incident.
"The process relies on pot luck as to whether or not more lives will be lost in similar circumstances in the future."
Thompsons Solicitors acted for the families of the dead in the Flying Phantom disaster and will be assisting with the legal aspects of the bill. Partner Patrick McGuire said: "Scotland desperately needs a FAI system which has teeth and will actually make a difference to the families who have lost loved ones. The current system is woefully inadequate."
A Scottish Government spokesman said: "The Justice Secretary gave an undertaking in January 2012 that a bill to implement the recommendations of Lord Cullen's review would be brought forward by the Government before the end of this Parliament. Many of Lord Cullen's recommendations were addressed to the Crown Office and Procurator Fiscal Service and have already been implemented.
"The Scottish Government will consider the content and detail of Patricia Ferguson's proposals when they emerge after consultation."