Establishing a beachhead on enemy-held turf is historically one of the most dangerous jobs in warfare, just ask Achilles . But the robotic age may make it slightly less so.

A research team from Stamford, Conn. has developed an amphibious drone that they are currently testing with the Marines. The GuardBot is a robot ball that swims over water at about 4 miles per hour and then rolls along the beach, at as much as a 30-degree incline and 20 miles per hour.

It uses a nine-axis stabilization, “pendulum motion” propulsion system, which moves the bot forward by shifting the center of gravity back and forth and a variety of steering algorithms.

It took creator Peter Muhlrad some seven years to develop, but now that it’s complete Muhlrad says it can be rapidly produced in various sizes. Company documents suggest it can be scaled down to units as small as 10 cm and as large as nine feet. The company is planning to develop a prototype that’s 6 feet in diameter.

Muhlrad’s company, GuardBot Inc. has a cooperative research development agreement, or CRADA, with the Navy. A CRADA is a legal framework that allows private companies or researchers to use government facilities, research and resources to build things that are mutually beneficial to both parties. The information that the researcher discovers is protected for up to five years. Under many CRADAs the researcher does not receive money from the government but has the right to commercialize what he or she produces. The government retains a use license.

Here’s the team presenting it at Marine Corps Base Quantico, in Virginia, in 2012. Watch it navigate the volleyball pit.