I do the first two types of dives, and at some point in the future I'll be doing the third. I'm not going to carry a beacon in my pocket or anywhere else.
My family know the calculated risks I take while diving - we've discussed them and I share my predive planning and risk analysis with them so that they're aware of what my dives entail. They also know that if someday I don't come back they shouldn't launch an extensive search for me. If I'm gone I'm gone and unless the ocean sees fit to return my remains that's where I'll be. My dive buddies know who gets which of my gear if I should die while diving, and my family members know that I love them.
I think the idea of a mandatory locator is overreaching authority, and no, I'm not a libertarian. I simply have no interest in such a device.
-Adrian
Again, forget about the word "mandatory". It's an unfortunate distraction from what is otherwise could be a very interesting thread. No one is going to force you to carry any type of dive gear (with the exception of a dive flag in a high traffic harbor, maybe). You want to dive the U-869 with an aluminum 80, go for it. My question is would anyone doing big dives voluntarily carry a beacon if it was cheap and small? If you wouldn't, that's fine, but it's an interesting discussion nevertheless.
I will also point out that while I don't know you or your family, I do know a bit about human emotions. The calm, clear discussion that you have had with them while you are sitting at the breakfast table may have a different conclusion than the one that they would have with the coast guard if you ever failed to return. Whatever they tell you now, they may feel very differently if it actually happens. And they might appreciate closure. Most families in this situation do.