At long last, the Scotsmen arrive at my own home country, Australia. Well, sort of, because the first Australian map doesn't take place on the mainland. Instead, the Scotsmen stop off at a small sandy archipelago in the midst of the Great Barrier Reef, where the Australian government has demanded the removal of a haggis factory set up to feed any Scottish tourists who may pass by.

This level is almost all water, with only a few small islands, and some shallows connecting them. Nothing grows on them except palm trees and oats (strangely enough). Enemies arrive from all directions via motorboats. The player would be wise to target the boats, while the enemies are clumped close together and in the open. Although there is only a small area to defend, the enemies can approach from any direction and quickly get close to the haggis factory, meaning the player won't simply be able to defend a front line while leaving their rear unguarded. The Great Barrier Reef introduces the first two Australian enemies, the Kangaroo Rider, and the Budgie Smuggler.

The kangaroo rider is a fast moving ranged unit with a twist. Unlike regular projectiles, the boomerangs that they throw don't follow a normal arc. Instead they throw them beyond their target, and they then hit them on the way back. This makes them very effective against units in cover. Their downside is their cost, mediocre health, and the fact that they present a large target, making them vulnerable to otherwise inaccurate ranged attacks such as the porridge cannon, turnip turret and plain old porridge bowls.

The budgie smuggler is unique among enemies in their ability to swim. This makes defending on water maps much more difficult, as they can traverse bodies of water that would otherwise serve to guard the player's flanks. On The Great Barrier Reef map in particular, this ability enables them to reach the haggis factory in seconds from any point on the map, where other units would have to take the long way around, using the shallows. In combat they are a melee unit of average ability, although they do cost slightly more than similar units such as the Frenchman, to take into account their swimming ability.