The Italian company of ARIS SpA (Applicazioni Rielaborazioni Impianti Speciali) has developed, as a private venture, a special kit to improve the amphibious capability of the now BAE Systems, Ground Systems Division M113 series full-tracked armoured personnel carrier (APC).

The first prototype of this vehicle, called the Arisgator was completed in 1997 and early in 1999 it was stated that the Italian MoD had awarded a low rate initial production contract to the company. The now BAE Systems, Ground Systems Division M113 series of APC are used in large numbers by the Italian Army and to a lesser extent the Marines. In mid-2006 it was stated that the Arisgator was in service with the San Marco Battalion of the Italian Navy Landing Forces.

The standard BAE Systems, Ground Systems Division designed M113 series APC is fully amphibious being propelled in the water by its tracks at a maximum speed of 5.8 km/h, which is adequate for calm water.

The M113 was not designed to operate in fast flowing rivers or to be launched from landing craft off shore.

To improve the amphibious characteristics of the M113 a special oceanic kit has been developed by ARIS, which enables the vehicle to operate safely in ship-to-shore operations as well as rivers.

This kit weighs between 1,350 and 1,700 kg including bow, roof and stern units, all of which are made of light alloy as is the basic M113 series hull.

A shaped front bow has been added to improve the buoyancy of the vehicle and two stern units are fitted, one either side of the rear ramp. Each stern unit incorporates a hydrostatically operated propeller, which can be driven independently allowing the Arisgator to turn upon its axis while afloat.

A snorkel is installed on the roof of the Arisgator to permit engine and personnel air breathing during water operation.

An extension has been fitted on the exhaust pipe on the right side of the hull roof and a special cover system has been fitted over the normal air inlet/outlets in the roof of the M113, to the right of the driver's position.

The normal commander's roof-mounted cupola and oblong hatch over the rear troop compartment have been retained as has the power-operated ramp in the hull rear. The overall sealing of the M113 series vehicle has also been improved.

The Arisgator can carry eight fully equipped troops and can also be fitted with various external weapon stations.

The upgraded vehicle is also being marketed with a turret armed with a 0.50 (12.7 mm) machine gun or a 40 mm automatic grenade launcher which can be fitted with various types of target acquisition systems including day/night sights and a laser range-finder.

The turret/weapon could also be fitted with a stabilisation system to allow stationary and moving targets to engage while the platform is stationary or moving.

Other options include additional armour protection and a new diesel powerpack consisting of a 300 hp diesel that meets EURO III requirements coupled to a new automatic transmission.

Based on their experience in the M113, upgraded to enhance its amphibious capabilities, ARIS have carried out a similar upgrade to the M548 full-tracked unarmoured cargo carrier, which is also a member of the M113 family of vehicles. As of mid-2007 this remained at the prototype stage.