I would imagine every crew has a wide range of ages already. They're not all gonna retire at the same time. Plus, whatever happens to the business would be a democratic decision by all workers, however they choose to structure that democratic process.
If you think that sort of process would fail, I'm not sure why you would support socialism at all.
That's not a judgment on you, to be clear. I'm relatively new to socialism, at least in terms of thinking of it in practical terms. Maybe there's a role for a bigger regulatory body to play in that system to ensure capital continues to be owned by the people who work with that capital (or owned by the broader community in which it resides).