Swiss Boat Skipper Theory (Kat. A/D) key terms

The international regulations for preventing collisions at sea, setting steering, sailing and light rules that apply on open water. Swiss inland waters add their own supplementary rules on top of these.

The boat that must keep its course and speed while the other gives way. On Swiss lakes this is often the vessel approaching from starboard, or a sailboat under sail against a motorboat.

The boat required to alter course or speed to avoid a collision, passing astern of the right-of-way vessel where possible. It must act early and clearly enough for the other skipper to notice.

A constant compass bearing to another vessel over time, which means a risk of collision exists even if the distance still looks large. Checking the bearing is the standard first step in any encounter.

Continuous watching and listening by sight and hearing, using all available means, so that hazards and other vessels are detected in time. A proper lookout is the first legal duty of every skipper.

A speed at which the boat can stop or turn within the distance needed, adjusted for visibility, traffic, waves, current and local speed limits. It is judged by conditions, not by the posted maximum alone.

Swiss regulations for lakes and navigable rivers that complement international rules, covering traffic side, speed limits, distances from shore and swimming zones. Skippers must know both sets and apply the stricter one.

A routing system with lanes, separation zones and crossing points designed to keep opposing traffic apart. In a lane you keep to the direction of travel and cross at right angles when necessary.

The lights a vessel must show between sunset and sunrise or in poor visibility: sidelights, sternlight, masthead light and all-round lights. Their colour and arrangement tell other skippers the type and heading of your boat.

A red light on the port side and a green light on the starboard side, each showing from dead ahead to 112.5 degrees aft. Seeing red means the other vessel is crossing towards your port side.

A white light on the fore-and-aft centreline shining forward over 225 degrees, required for power-driven vessels underway. Sailboats under engine also show it, which is how you recognise a yacht motoring.

A white light at the stern shining aft over 135 degrees. Together with the sidelights it completes the 360-degree picture other vessels use to work out your course.

A single light visible over 360 degrees, used for anchored vessels, small craft, and special meanings such as a red over red for not under command. It is not tied to a heading.

A white all-round light shown at night when anchored outside a harbour or mooring area, so other vessels know you are stationary. In designated berths it is usually not required.

Black shapes hoisted by day to signal status: a ball for anchoring, a cone pointing down for a sailing vessel under engine, a cylinder for constrained by draught. They carry the same information as lights do at night.

Short and prolonged blasts on the horn or whistle used to indicate manoeuvres and warn of danger, such as one short for altering to starboard. In fog, vessels also give regular whistle signals by category.

Any internationally recognised sign of grave danger needing immediate help, such as MAYDAY by radio, red flares, a waving square flag, or slow raising and lowering of arms. Using one falsely is an offence.

The spoken distress call used on VHF channel 16 when life or vessel is in immediate danger. It is sent three times, followed by identity, position, nature of distress and number of persons aboard.

Buoys marking the sides of a channel, normally red to port and green to starboard when entering from seaward or as defined locally. Their shape, colour and topmark tell you which side to pass.

Yellow and black buoys with two cone topmarks that indicate safe water lies north, east, south or west of the mark. The number of cones and their direction give the compass sector.

The international standard for buoy shapes, colours, topmarks and light rhythms, split into region A and region B for lateral marks. Switzerland follows region A, with red to port on entry.

A yellow buoy or post with a yellow cross topmark marking a special area such as a swimming zone, pipeline or racing course. Its light, if any, is yellow and the meaning is given on the chart.

A scaled map of a water area showing depths, hazards, buoys, shore features and symbols. Reading chart symbols and checking the edition date before a trip is basic preparation.

A line on the chart joining points of equal depth, with the sounding value printed along it. Contours let you see where shallow shelves rise and plan a route with a safe margin.

Securing a boat to a fixed point such as a buoy, jetty or pile using lines. In Swiss harbours berths are often assigned, and you leave enough slack for water-level changes.

Holding the boat in place by lowering an anchor on chain or rope until it bites the bottom. You pay out scope, check the anchor holds by taking a transit, and hoist an anchor light at night.

The ratio of anchor line length to water depth, typically around five to seven times depth for rope. More scope improves holding but increases the circle the boat swings through.

The circle the boat traces around its anchor as wind or current shifts, set by the amount of scope out. You must anchor so this circle clears other boats, buoys and the shore.

A mooring line led fore or aft at an angle to stop the boat moving along the berth. It is the line that lets you leave a berth cleanly by motoring against it.

A slow speed at which the propeller still bites and the boat answers the helm, used in harbours and tight berths. Wind and current often matter more than throttle at these speeds.

The point around which the boat turns when the rudder is applied, roughly a third of the length from the bow when moving ahead. Knowing it helps you judge clearance at the stern.

The sideways push of the propeller, strongest in reverse, that swings the stern to one side depending on rotation direction. Skippers use it deliberately when docking rather than fighting it.

The flashing pattern of a buoy light, described on the chart as flashing, isophase, occulting or a group of flashes. Matching the rhythm to the chart confirms you are looking at the right mark.

A scale from 0 to 12 describing wind strength by its visible effect on water and waves. It helps you estimate conditions without instruments and judge whether to leave shelter.

A warm, dry downslope wind common in Alpine valleys that can arrive suddenly and create violent gusts on lakes. It is a key local hazard in Swiss weather reading.

A published prediction of wind, visibility and precipitation, in Switzerland often including lake-specific wind warnings. Checking it before departure and monitoring updates is part of passage planning.

The practised sequence for recovering a person who has fallen in: shout, throw flotation, mark the position, return and recover. Immediate action and keeping the person in sight matter more than speed.

Personal flotation device sized to the wearer, worn rather than stored, with a whistle and often a light. Swiss rules require one suitable device for each person on board.

A portable extinguisher carried aboard and checked for pressure and date, aimed at the base of a fire. Fuel and electrical fires need the correct agent, and you shut off the engine first.

The lowest inside space of the hull where water and fuel vapours collect. It is checked before starting the engine and pumped out, since accumulated vapour is an explosion risk.

The water or closed-circuit system that keeps the engine at working temperature, with an intake that can clog with weed or plastic. A weak telltale stream is an early warning to stop and check.

A lanyard attached to the skipper that stops the engine if they fall or move away from the helm. It is required on many small powerboats and should be worn, not clipped to the seat.

A knot forming a fixed loop that will not slip under load yet unties easily when slack. It is used for mooring lines and for securing a line around a post or ring.

The standard way to secure a line to a cleat with a full turn, figure-eight turns and a locking turn. It holds under load and releases quickly when needed.

The Swiss permit required to command a motorboat above a defined engine or sail area threshold, issued after theory and practical examination. Categories differ for inland and sea use.

The official entry of a boat in the cantonal or national register, giving it a number and plate. Unregistered or uninsured boats may not be used on public waters.

The waves a moving boat leaves behind, which can erode banks, disturb moored craft and endanger swimmers. Speed limits near shore exist largely to keep wash within acceptable limits.

A marked or charted area where a maximum speed applies, often 10 km/h near shore and less in harbours or swimming areas. Limits are shown on signs and lake charts and are enforced.

The international calling and distress frequency monitored by rescue services. You call on 16, then move to a working channel for routine conversation to keep 16 clear.