When sourcing marine radar, you must prioritize Transmitter Power (kW), which determines the detection range and ability to penetrate heavy rain or fog. For commercial vessels, X-Band (9 GHz) is essential for high-resolution target detection, while S-Band (3 GHz) is superior for foul weather penetration. Additionally, ensure the unit features Automatic Radar Plotting Aid (ARPA) capabilities to track multiple targets simultaneously and calculate Collision Avoidance data like CPA (Closest Point of Approach) and TCPA (Time to Closest Point of Approach).