Comark Announces MDU42 Large Screen Marine Display Passes Military Testing. Comark Corporation, a leader in the design and manufacture of ruggedized computer and display solutions for the marine and military markets, announced the availability of the MIL Certified MDU42. This 42” Marine Display Unit successfully passed MIL-STD 901D, Grade A, Medium Weight Testing; MIL-STD 167- class 1, type A; MIL-STD-810F; and MIL-STD-461E. These certifications are standard requirements for equipment used on Navy Surface ships.