I'm considering using ferries as part of my visit to South Korea, either to visit a Korean island, such as Jeju island, or to travel to or from Japan. Partially for the novelty, and partially because it's more flexible.
While looking up Jeju island on Wikivoyage, there was mention of a major ferry disaster with hundreds of lives lost.
How safe is ferry travel within or to and from Korea? Is it about as safe as air travel, riskier, or less risky? Does choosing the right company, or avoiding bad sea conditions help?
Related resource: List of South Korean ferry disasters