The game.. plan?

I think this will need some tweaking, as I'm not sure if this is legal (or safe).

Basically, there are two teams:

The bomber team
The team that drops the water balloons from the top story of the play zone. Consisting of 2 or 3 players. Their objective is to drop the balloons from the top story in a way that their two/other team mate on ground level can catch WITHOUT it breaking.

The interceptors
This team is stationed on various stories between the top level of the play zone and the ground level (with buckets). They must use their communication and co-ordination skills to intercept as many of these balloons to prevent the other team from achieving the maximum number of balloons caught. This team consists of 2-4 players approx, depending on the size of the play zone. The interceptors must also be careful not to break the balloons (they will obviously get wet :P) and they do not score unless the balloons are intact.

The scoring system
After each round each teams intact water balloons will be weighed. After four rounds (two rounds each as playing as the bombers) the team with the heaviest weight/highest score wins.

Complications
The bombing team have the choice to fill their own balloons to any specification they wish. This could be all small balloons - relatively light, so low scoring, but less likely to break, big balloons - travel faster, easier to break, but score higher or a mixture of both and everything in between.
Interceptors cannot clean out their buckets between each catch. If their bucket gets full they can no longer catch for that round, if they are exceptionally good at catching however, they may switch with another station that has an emptier bucket. Additionally, the more water balloons in the bucket whilst catching new ones the more likely the already caught ones will pop.

The game flow:
At the start of each round both teams start at ground floor. They may/may not (haven't decided yet) have collaboration time beforehand to decide on strategy.

As the sound (horn? whistle?) goes, both teams must get into their places. The interceptors have less to travel with light buckets. The top bomber has a huge bucket of water balloons which is relatively heavy. If there are 3 bombers, only one needs to stay at the bottom, so the third may help to carry it up. However, should the third help carry it up the bomber cannot start throwing until they are back at the bottom.

In the middle of each round, both teams are then allowed to switch stations between their own ranks. It is mandatory for the top bomber to switch with one of the ground bombers. The ground bomber chosen must start climbing the stairs as the top bomber descends, but the top bomber must also carry whatever water bombs left with them down.

Once both bombers meet they will continue up and down depending on their station, but the previous top bomber will give their left over bombs to the previous bottom bomber. They must choose whether to have the top bomber move slowly so the bottom bomber has less to carry back up the stairs, or to meet approximately middle to meet up faster.

Once the new top bomber takes their station at the top of the play zone interceptors must cease switching places.

Edited with test -:
[Whilst the bombers are switching places the interceptors have to wait a minute (60 seconds) then are allowed to scale to the higher bomber floor to 'steal' balloons, but only one at a time. Meanwhile, bombers who pass the interceptor level/s can steal from interceptors but ONLY if it is unguarded (no tackling :P). This means that the interceptors can send everyone up to steal balloons or leave someone behind to guard their stash.]

That was a lot of writing. I think that was our general idea though. We need to tweak it according to how the game plays. Or we can come up with an entirely new idea and establish those rules quickly if you're all feeling unsure. I'm easy :)