[samdive]

Spoke to Ryan - he gave me some more info on what the D4 tells you when you're on the surface - sounds much better than the D6/D9

"On Surfacing you will see the details from your last dive and your
surface time will count up in seconds with a variable surface time alarm.
We also have alarms for max depth and a depth notify alarm.

The unit has a sample rate of 3 times per second and then logs the
deepest of those 3 to the logbook every second so this should give a better
picture of the dive profile.

The unit has a daily and total free dive history that is separate to
the scuba history."

I should have one to play with for a while when it's released properly after Christmas

S