"Rim of the Pacific" training was a day at the beach for sailors and Marines involved in Sunday's amphibious assault.
The troops not only faced the challenge of getting to shore, but also the added challenge of communicating between different countries.
While many RIMPAC exercises have taken place far off the coast, this time the action came ashore at Bellow's beach.
"The biggest challenge was getting from the ship to the shore," said 1st Lt. Tyler Kistner, with the U.S. Marines.
As helicopters circled overhead, Amphibious Assault Vehicles rolled out of the surf and onto the sand, followed by a landing craft that rode on a cushion of air to reach the beach. Inside there were forces from Australia, Tonga and the United States.
"The biggest thing was the communication -- that mutual understanding with one another. We have to work together, not just say 'I'm U.S. and you're Australian. Let's just try this,'-" said Kistner.
Communication was also key in the planning of this massive drill.
U.S. forces may have rolled up on this beach before, but for other countries it was a first -- including Japanese reconnaissance teams that scouted the shore long before the vehicles arrived.
After making sure the sands were safe, the forces then pushed inland with their sights set on a makeshift town. There they practiced for urban warfare.
"We have a developed town and opposing forces.They had to push through and take out this insurgency that we developed in this training situation," stated Kistner.
The exercise not only provided important real-life training for those involved, the U.S. Marines felt it also sent an important message out to the rest of the world.
"This was huge because it showed that the United States doesn't stand alone. We have other partners around the world that have one united stand, one purpose," added Kistner.
On Tuesday, there will be another amphibious assault on Oahu's Windward coast, as U.S. Marines join forces with troops from Indonesia and Mexico.