Have a look at the Citizen Eco drive range. 15 minutes in bright sunlight runs it for up to 6 months and pro rata for indoor lighting. Displays one zone with hands, another on a digital display and UTC at all times on another small set of hands. 24 hour stopwatch, alarm, back light, radio controlled for time accuracy. When I was 2 weeks out of the radio reception area it was 2 seconds wrong when back in area so it is good worldwide really. Says resistant 200 metres so should be OK for some scuba diving. Simple conversion tables on a slide rule. Worth a look?