Under COLREGs Rule 6 (Safe Speed / Velocidad de Seguridad), which combination of factors must be taken into account by all vessels to determine a safe operating speed?

1. State of visibility, traffic density, vessel maneuverability, wind/sea/current conditions, proximity of navigational hazards, and depth of water relative to draft
2. Vessel engine fuel consumption and passenger arrival schedule only
3. Maximum hull speed specified by the boat manufacturer under calm test conditions
4. The speed of the fastest commercial vessel operating in the vicinity