Eh, I don’t think their families should pay, they aren’t the people using the emergency services time and it’s pretty scummy to charge someone for something their relative did. As far as this case goes, I feel like if anyone should pay for the rescue efforts, it should be the company that operated the thing. It’s not exactly like the passengers called an emergency in when not in danger, wasting their time: after all, they didn’t call it at all, and it was a real emergency. The way I see it, the company involved was offering a service, and as such had a duty to ensure they could deliver their service safely, both in adequately designing their sub for the task and on having reasonable safety equipment both on and off the sub to handle the most foreseeable problems (for example, they could have had tracking bouys that detatch from the sub to help track it in case it lost communication, which could have made the search easier). The company failed to do this, and so it was their actions that resulted in the use of emergency services time and resources.