It was a major British scandal of the mid 19th c., the Coffin Ships. I wrote about it earlier here .

The shipowners had powerful incentives to cut costs on their vessels- the profit margins had become quite small, and so shoddy boats were built and poorly maintained. And , once signed, seamen could be forced to man them. The insurance industry was not well suited to stop it: enough underwriters could usually be found to insure even a dangerous boat. And the shipowners were well-represented in Parliament, and so were able to resist reforms and regulations.