Ten people died while diving in New Zealand in 2019, and it seems all deaths were preventable.
The number one issue reported is that divers in trouble failed to ditch their weight belt or integrated weights; too many dead divers were found on the bottom with their weights still in place.
So, ditch your weights if you need to. They cost little when compared to your life.
The second cause is laid at the feet of divers diving alone: too may deceased divers have failed to stay with their buddies, and, when a problem occurs that could be resolved with assistance, there is no one to help. These days, a lot of people dive with "same ocean," buddies. It's not good enough when a problem arises.
The third cause: diving when not medically fit. Something like a third of divers who die have heart issues, and to many of them, their heart disease was unknown. The stress of diving, particularly on the surface in choppy water, can be a killer. Divers, especially those of us over 45, should have an annual medical examination, including periodic visits to a cardiologist.