1) The screen is getting a bit complex: it might be an idea to have separate views for different tasks
2) Example of different views:
a) Chart all screen
b) Chart half screen, other half four numbers (configurable)
c) Numbers eight numbers (configurable)
d) Route editor
e) Way point editor
f) General settings
3) Lower control area: at the bottom rather than lots of buttons have just a few, e.g.
a) arrow button to previous view
b) button to bring up configuration options (show / hide ruler, waypoints etc)
c) user configurable / multi-mode button
d) arrow button to next view
4) Numbers in views b) and c) should be selectable from:
a) latitude
b) longitude
c) predicted depth
d) predicted tide rate
e) predicted tide direction
f) course over ground
g) speed over ground
h) distance to next waypoint
i) velocity made good to next waypoint
j) predicted time to next waypoint
k) distance to end of route
l) predicted time to end of route (you will not believe how long people will spend looking at this particular entry, particularly at 3 in the morning)
m) current waypoint number
5) Route screen used to create, modify, select, delete a route, with action button to select next active waypoint and setting option to specify distance to waypoint that counts as reaching it
6) Waypoints screen should allow a database of waypoints to be managed i.e. added, modified, deleted, with configuration options including latitude, longitude, name
7) When entering latitude / longitude it could be ok to use the standard keyboard but it would be nice to pre-select that its in number mode not character.
8) Actually, do what most software developers do and "borrow". Go buy a yacht racing GPS unit, see what functionality it offers and how its interface works, then try to make it better.
