Marine Insurance covers the hull of a ship, and not necessarily its contents. It's the kind of insurance that ship owners buy when they are launching a big tub and want to be sure they don't lose the entire thing to an ocean disaster like that suffered by Titanic.
Now, when the Space Shuttle Challenger blew up, the space shuttle program had to shut down for a long time because it became very difficult to find an insurance company willing to back a project as expensive as a space shuttle, especially when it was crystal clear that the insurance company could watch the whole thing blow up in its face.
The insurers of large passenger ships were looking at a similar problem in 1912, after the Titanic sank. She was supposed to be an unsinkable ship, a safe bet. She wasn't.
If her sister ships, like the Olympic and Brittanic, are not entirely a safe bet and the chances of this ship sinking seems to have gone way up, then a smart insurance agent will raise the price way up. No more cheap insurance for vessels like this -- and that's true of all large ocean vessels, not just White Star Line vessels.
Get the idea? The sinking of the Titanic was a golden excuse for marine insurance agents to suddenly jack their rates through the roof on every ship out there. Who ever was in the marine insurance racket not had an excuse to scalp every single one of their clients, or at least raise the rent on insurance by a big bump.
Did that happen? Did everyone get bit, or just the big shipping lines? Who made money and who lost money as a result?