Aids to navigation
Buoys and daymarks are road signs on the water. ASA 101 expects you to identify color, shape, numbering, purpose, and the skipper action they imply in familiar local waters.
Saved buoyage trainer
Saved locally in asa101.navigationAids.v1. It backs up from Progress backup and feeds Readiness and Exam cram.
Harbor marks challenge
Apply the marks as a skipper entering a harbor, choosing the track that keeps the boat in the channel and respects junction, safe-water, special, and regulatory marks.
Harbor pilotage checkoff
A practical local-water drill: brief the direction of buoyage, follow the marks, identify hazards, call traffic limits, and name a bailout. Saved under asa101.navigationAids.v1.pilotageRuns.
Choose a pilotage station.
Red, right, returning
In the U.S. lateral system, when returning from sea or traveling upstream, red even-numbered marks stay on your starboard side and green odd-numbered marks stay on your port side. The numbers generally increase as you return from sea.
Green cans
Green, odd-numbered port-side marks. Can buoys have a flat cylindrical top. Keep them to port when returning.
OddPort when returningRed nuns
Red, even-numbered starboard-side marks. Nun buoys have a conical top. Keep them to starboard when returning.
EvenStarboard when returningPreferred channel
Red-and-green marks show a junction. The top color indicates the preferred side to pass on when following the main channel.
JunctionTop color mattersOther marks
| Mark | Meaning |
|---|---|
| Safe water mark | Red and white vertical stripes. Navigable water all around; often marks a fairway, mid-channel, or approach. |
| Special purpose mark | Usually yellow. Marks anchorage, spoil area, cable, race course, or other special area; read the chart. |
| Information/regulatory mark | White with orange symbols. Gives directions, warnings, controlled areas, exclusions, or hazards. |
| Dayboard | Fixed sign on a post or structure. Shape/color match the buoyage system; match it to the chart. |
Navigation lights
Even if ASA 101 sailing is daylight-oriented, the standard asks you to identify required lights on a recreational vessel. Learn the basic picture:
- Red sidelight: port side.
- Green sidelight: starboard side.
- White sternlight: visible from aft.
- All-round white light: common anchor light or small power configuration depending on vessel type.
Practice the red, green, and white light combinations in the navigation lights trainer.
Sound signals you should recognize
Navigation Rules include sound signals for meeting, crossing, overtaking, restricted visibility, anchoring, and danger. ASA 101 does not require memorizing every commercial signal, but beginners should know the danger signal: five or more short blasts means "I do not understand your intentions" or "danger." In fog, a sailing vessel underway sounds one prolonged blast followed by two short blasts at intervals of not more than two minutes.
Commercial traffic
A 25-foot sailboat is maneuverable compared with a ship in a channel. Never impede traffic that can safely navigate only inside the channel. Cross behind, stay predictable, and communicate early if your intentions are unclear.
Sources
- BoatUS Foundation Aids to Navigation - lateral marks, red right returning, numbering, and channel-marker basics.
- US Sailing Basic Keelboat - includes local-water aids-to-navigation response and close-quarters skill expectations.
- American Sailing ASA 101 - beginner keelboat scope for sailing language, sail handling, and safe navigation.
- NOAA Nautical Charts AIS Aids to Navigation portrayal - chart and real-world buoy symbol examples.
- NOAA U.S. Chart No. 1 - official chart-symbol reference for lateral, safe-water, special, and regulatory marks.
Run pilotage checkoffPractice buoyageLights trainerSound signals trainerStudy right of way