Sail Skills - ColRegs Free Guide to ColRegs (the International Regulations for Preventing Collisions at Sea, the IRPCS or Collision Regs).  Guidance covers all aspects with animations, pictures and diagrams.  Aimed at small vessel users but suitable for professional mariners.  Especially recommended for RYA examination candidates.
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Rule 25 Sailing Vessel Underway  Animation:  under 7m underway ColRegs Home>ColRegs>Lights & Shapes>Animations>Sail and Oars>Sailing Vessels Underway Under 7m Sailing vessel underway based on three vessels, one displays: combined lantern sidelights and sternlight lighted lantern to prevent collision back to top A sailing vessel under sail and power - displaying a cone, point downwards Vessels under sail and power Vessels under oars A small boat under oars Sailing vessels under 7m A sailing vessel (a dinghy) under 7m Sailing vessels under 20m A sailing vessel (a sloop) under 20m Sailing vessels optional lights A large vessel under sail showing optional lights on her mast Sailing vessels general A large vessel under sail