The Army isn't quite known for its fleet of watercraft, but during a computer-simulated exercise like Yama Sakura that occurs in a country comprised of thousands of islands, leaders say they are invaluable.

The boats aren't real, but they're part of a scenario that is designed to be as realistic as possible. Given the terrain in this particular scenario, watercraft can make a big difference.

"There are a lot of uses for Army watercraft during this exercise because, of course, Japan is an island nation," said Chief Warrant Officer 3 Robert Penner, sea mobility officer in charge with the 593rd Expeditionary Sustainment Command. "During this exercise the Japanese will not have any logistics watercraft, so it's helpful for them to see how we operate."

Yama Sakura is an annual bilateral command post exercise between Japan and the U.S. that runs from Dec. 2-14 on Camp Asaka, Japan. During the exercise, the command is the focal point for logistical support on the simulated battlefield.

Penner said his notional fleet of 30 watercraft, supplying units near coastal areas that run low on critical items such as fuel and ammunition, are a perfect example of what makes sustainment critical.

During their time in Japan, the command will simulate in-processing Soldiers, providing rear security and transporting necessities of war, all while working and integrating with the Japan Ground Self-Defense Force and I Corps.

"The partnership with the Japanese has been phenomenal, and the integration and learning that we're experiencing together could not be better," said Brig. Gen. Kurt Ryan, commander of the 593rd ESC. "It is one of our top training objectives to understand interoperability with the JGSDF."

Ryan said his unit is also working with Japanese civilian agencies and cabinet members who work with transportation, humanitarian assistance and disaster relief in order to be better prepared to assist during a natural disaster.

"We are integrally plugged into I Corps headquarters for mission command, and we are bilaterally connected with the Eastern Army," said Ryan.

Ryan said his unit is also staying connected to bilateral working groups that are key to allowing I Corps and the Japanese Eastern Army to fight the enemy.

Because Penner is in charge of the only watercraft capable of conducting logistics during the exercise, he said coordination with his Japanese counterparts has been vital.

"We've been working with the Japanese a lot during the exercise. We actually offered the Japanese a chance to put some supplies for their units onto one of our boats," said Penner. "I ended up creating a boat just for their resupplies, so now they are going to have their own watercraft to use.

Ryan said he enjoys having the opportunity to work in a high intensity environment like Yama Sakura.

"We always want to get better integrating with I Corps because that's who we support," said Ryan. "I wake up every day asking 'how can I sustain America's Corps', that's my task and purpose, and that's the command's task and purpose."

For Penner, the exercise has been a way for him work with Army watercraft on a scale much larger than he is accustomed too.

"[An exercise of this size] is