I like this game, but I have a few variations:
The game starts in the centre of the designated area, or at least equidistant from both teams base camp/spawn point. The spawn points will be equipped with the same amount of water for both teams. (adjusted per team sizes and load-outs as needed)
Clues are interesting, but what I would like to do is have each team hide the same number of flags in their opponent's area. That way, when the game starts, everybody is looking for flags, while heading towards enemy territory where they know flags can be found.
It would be ideal for spawn points to have an "overseer" who would count every player who returned there as a point for the enemy team. A player can only return to spawn if they have been hit (or, being completely out of water, decides to give the point up for the sake of refilling).
Alternatively, every player starts the game equipped with a flag of their teams color. So if a player is taken out, the enemy grabs their flag. Also, enemy flags should be worth more points. I would like to discourage team members swapping flags with each other freely, but some would call this "strategy" instead of "cheating".
And a further thought on this, each player needs at least one of their own team's flags to go out and fight. The spawn zones contains several extra flags for that team. So players have to play smart, and not use up too many flags/lives. Teams can store their own extra recaptured flags at their base, but not enemy flags. They must carry all enemy flags with them, but they can be distributed among team members for strategy.
Man this sounds like fun.