When sourcing dive lights, prioritize Lumen output (brightness) and Beam Angle. For recreational diving, 800 to 1,200 lumens is standard, while technical diving or underwater photography may require 3,000+ lumens. Ensure the light uses high-quality LEDs (like CREE or Luminus) for longevity. Additionally, check the Color Rendering Index (CRI); a high CRI (>90) is essential for capturing true colors underwater. Battery life is critical—look for rechargeable Li-ion batteries (18650 or 26650) with a burn time of at least 90-120 minutes at maximum output.