That will be helpful during everyday endeavors

Because watches these days tell you so much more than the time, you should probably focus on a watch with other features. The watches I will list each do more than just tell the time and date. Some of the most desirable functions are; a chronograph, temperature gauge, tide graph, equation of time, moon phase, GMT indicator, perpetual calendar, and a rotating bezel. Next, there is the distinction between an automatic and quartz movement. If the watch needs a battery, it is a bad option. Batteries run out, and then the watch is useless to you, unless the right type of batteries seem to wash shore often enough. The only type of quartz movements which are even feasible are those which are solar powered (such as the Citizen eco-drive, or certain Casio watches), or movement powered (Seiko Kinetic or Spring Drive). There are a few such quartz watches, but perhaps they cannot stand up to the powerful mechanical automatic watches. On the other hand, a completely digital watch has no moving parts. If the case is study enough, it can take almost any amount of beating. This is a plus compared to mechanical watches with delicate insides. In terms of the automatic mechanical movement, you have an mechanical movement that winds automatically when you wear the watch. This means that you need to be wearing the watch most all the time to ensure that it is accurate, otherwise the watch will stop. There will be deviations however, and it is impossible for almost any watch to remain fully accurate. Even the best mechanical movements lose or gain a couple of seconds each month. Unless you have some very accurate sundials, it will be difficult to maintain the right time over a period of years. Which brings up two good points. One, that you should have a sundial. They are easy to make as long as you can accurately mark the circle around the stick which draws the shadow. Using this in conjunction with a wrist watch will help you ensure your time keeping is accurate. The second point this brings up is that you most likely do not need a watch that is so accurate. While it would be nice to know when 10am is each day, what is more important is being able to measure time intervals, not the time itself. Life on an island is contingent on many things which have cycles, from tides, to weather, and wind cycles. It is important to able and measure long measurements in time to allow you to anticipate what your actions ought to be; when to fish, when to set sail, when it will rain. This does not mean that your watch needs to have a full calendar, but you need to have the ability to measure out the days and months in preparation for daily or seasonal changes. This can most likely be done by combining some system of marking a makeshift calendar with your watch in indicating the passage of the days and months.