It s important to have a basic understanding of common nautical terms associated with the parts, positions and directions of your vessel. Knowing these terms will make it easier to communicate with people aboard the vessel. Having a working knowledge will also prove useful especially when communicating with passengers, crew, emergency or maritime authorities. The following illustration names the main exterior parts of a vessel. Transom refers to the wide, usually flat area at the very back of a boat, where an outboard motor is typically mounted. Gunwale (pronounced gunnel) the upper edge of a vessel s side. Length overall refers to the distance between the hulls forward most and aft most extremes, excluding bolted on extensions. In the bow this would include a moulded anchor platform, but not a bowsprit.in the stern it would include a moulded swim step, but not stern drive propeller. Waterline length indicates the vessel s length at the water surface. The keel is designed to control a vessel s stability in water, helping it to move through the water rather than side-to-side. The bilge is an area where water and oil collects and may need cleaning and pumping out. Checking the bilge is a key pre-departure check which should be completed prior to every trip out on the water. Length Overall Rear of a vessel STERN: TRANSOM: Stern cross section usually flat area at the very back of a vessel GUNWALE: Upper edge of a vessel s side CLEAT: Metal fitting on which rope can be fastened SKIPPER 1 Front of a vessel BOW: BILGE: The internal compartment at the bottom of the hull HULL: Main body of a vessel KEEL: Lowest part of the hull in the water Waterline Length Main exterior parts of a vessel 1 Nautical Terminology 2017 National Maritime College
Directions and positions The terms forward and aft are used to indicate locations and directions on the boat. Ahead and Astern indicate locations or directions beyond the vessel. Sideways directions are considered Abeam with the left side ofthe vessel called Port and the right side Starboard. Beam refers to the width at the vessel s widest part. Port and Starboard Quarters refer to the hull area between the beam to the stern. Freeboard, an important factor in vessel stability. Freeboard refers to the distance from the waterline to do the lowest point of a vessel s deck. It s an important measurement as it determines how much weight a vessel can carry or, how it will perform in wind and waves. Waterline is the line (on the hull) at which the vessel sits in the water when it s properly loaded with passengers and equipment. Draft is the depth of water that your vessel needs in order to float freely. The draft is measured as the distance from the waterline to the lowest point of the boat. 2017 National Maritime College Nautical Terminology 2
Wash and Wake Engine idle, no wash or wake. Vessel flat in the water. Engine just above idle. Small wash no wake. Vessel still flat in the water. 6 knots is the fastest you can travel without creating a wake. When operating a power-driven vessel at 6 knots or more the safe distance off rules apply. 3 Nautical Terminology 2017 National Maritime College
As power increases the stern is forced lower in the water creating a rolling wake accross the back of the vessel and the bow rises up. This wake is the primary cause of damage to marine structures and shores causing bank erosion. In addition wake poses an additional threat of injury to people on anchored/ moored vessels and near boat ramp areas, jettys, wharves and marinas. The vessel is now accelerating and has started to plane or rise up and skim on top of the water instead of ploughing through it. Minimal wash and wake is created. 2017 National Maritime College Nautical Terminology 4
Safe Distances Off When travelling at speeds of 6 knots or more a vessel must keep certain distance away from others as follows: 30 metres from moored or anchored vessels, shoreline, structures, including; jetty s, bridges and navigation marks. Or, if that is not possible a safe distance. 30 metres is equivalent six, 5 metre boat lengths. 60 metres from a person in the water. This includes kayaks, row boats and sailing dinghies. 100 metres from a dredge, marina, work barge or vehicle ferry if you are travelling faster than 4 knots 200 metres distance from a power cable when anchoring. 200 metres If towing aerial equipment (e.g. paraflying) from any bridge, cable, wire, pipeline or structure. 500 metres out from shore between surf patrol flags or signs. A designated swimming area in a surf zone is defined as the area extending 500 metres out from shore between surf patrol flags or signs. Maintain a safe distance from any vessel towing a person. 5 Nautical Terminology 2017 National Maritime College
Swimming and Surf Zones All vessels must stay out side designated swimming areas and power-driven vessels smust not come within 60 metres unless permitted by signage. NSWRMS reproduced for educational purposes. Designated surf zones are areas extending 500 metres out from shore between surf patrol flags or signs. A designated swimming area in a surf zone is defined as the area extending 500 metres out from shore between surf patrol flags or signs. In all other areas a swimming area is defined as the area extending 60 metres out from shore between signs for swimmers. A person must not operate a vessel within 60 metres of a swimming area and the flags or signs marking these zones unless it is a vessel operated by Surf Life Saving Council lifeguards or unless permitted to so by a sign. These rules apply to all vessels including PWC. 2017 National Maritime College Nautical Terminology 6
Steering Rules NAUTICAL TERMINOLOGY Boat 1 (US) observes Boat 2 dead ahead on a collision course. Both Skipper s must alter course to starboard (right) to pass well clear of each other passing port (left) to port. Boat 1 (US) observes Boat 3 approaching from the starboard (right) on a collision course. Boat 1 must give way to Boat 3 by slowing, stopping or altering course to starboard to GIVEWAY. Boat 1 (US) observes a Boat 4 approaching on a collision course from the port.(left) We have the right of way and maintain our course and speed. If boat 4 does not attempt to alter or change course course to give way to Boat 1 (US). Boat 1 must take evasive action to avoid a collision by first sounding 5 short blasts.stop, alter course to starboard. DO NOT ALTER COURSE TO PORT and make every attempt to avoid a collision. Boat 1 (US) observes Boat 5 (yacht) MUST giveway, alter course to starboard and pass astern (behind) the yacht. Boat 6 is overtaking and must keep clear of Boat 1 (US) passing either side. Boat 1 (US) maintains course and speed. 7 Nautical Terminology 2017 National Maritime College