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| author | Claude <noreply@anthropic.com> | 2026-04-11 02:36:34 +0000 |
|---|---|---|
| committer | Claude <noreply@anthropic.com> | 2026-04-11 02:36:34 +0000 |
| commit | d5e819e869f3b15da0f28ba2d8525e825afeb5a0 (patch) | |
| tree | 78ae008c64934fadee7fb20f76b4d90237f67cf9 /android-app/app/src/main/assets/docs/sailing_reference.md | |
| parent | fc7192288109fc3542670cbeeaebe0de2a75eb74 (diff) | |
| parent | 4a2d0298ab2caa3d62cfbd54c0071ae47eb89ccf (diff) | |
Merge branch 'claude/particle-wind-simulation-IMVxT'
Particle wind animation, Learn tab, log text/photo, departure picker,
outbound link markers, offline ColRegs + sailing reference content.
https://claude.ai/code/session_01HXPjBsogsJVRwCiekDGkJX
Diffstat (limited to 'android-app/app/src/main/assets/docs/sailing_reference.md')
| -rw-r--r-- | android-app/app/src/main/assets/docs/sailing_reference.md | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/android-app/app/src/main/assets/docs/sailing_reference.md b/android-app/app/src/main/assets/docs/sailing_reference.md new file mode 100644 index 0000000..7fc7bdb --- /dev/null +++ b/android-app/app/src/main/assets/docs/sailing_reference.md @@ -0,0 +1,206 @@ +# Sailing Quick Reference + +--- + +## Points of Sail + +The point of sail describes the angle between the boat's heading and the true wind direction. + +| Point of Sail | True Wind Angle | Description | +|---|---|---| +| In irons | 0–30° | Head-to-wind, sails luffing, no drive | +| Close hauled | ~30–45° | Sailing as close to the wind as possible | +| Close reach | ~45–60° | Between close hauled and beam reach | +| Beam reach | ~90° | Wind directly abeam — often fastest point | +| Broad reach | ~120–150° | Wind on the quarter — comfortable, fast | +| Run | ~150–180° | Wind from directly behind | + +**No-go zone:** ~0–30° on either side of the wind — the boat cannot make progress sailing directly into the wind. + +--- + +## Tacking vs. Gybing + +**Tacking** — turning the bow through the wind (bow crosses the wind). The boom swings across from one side to the other. Used to head upwind. + +**Gybing** — turning the stern through the wind (stern crosses the wind). The boom can swing violently — always control the mainsheet. Used to change direction downwind. + +--- + +## Sail Trim Basics + +**Telltales** — strips of yarn or fabric on the sail. +- Both telltales streaming aft → sail trimmed correctly +- Windward telltale lifting → sheet in (trim), or bear away +- Leeward telltale lifting → sheet out (ease), or head up + +**In irons fix:** Let sails luff, push boom to one side, fall off onto a tack. + +**Reef** — reducing sail area by partially lowering the mainsail and tying off the excess. Reef before you think you need to. Typical thresholds: first reef ~15–18 kt, second reef ~21–25 kt. + +--- + +## Hull Speed + +The theoretical maximum displacement hull speed: + +**Hull speed (kt) ≈ 1.34 × √(waterline length in feet)** + +| LOA | Hull Speed | +|---|---| +| 20 ft | ~6.0 kt | +| 23 ft | ~6.4 kt | +| 30 ft | ~7.3 kt | +| 40 ft | ~8.5 kt | + +A modern fin-keel boat can exceed hull speed in planing conditions (surfing downwind in big waves). + +--- + +## Navigation Lights — Quick Reference + +| Situation | What You See | What It Is | +|---|---|---| +| Red + green + white | Two side lights + stern | Head-on approach | +| Red only | Port sidelight | Vessel crossing left-to-right in front of you | +| Green only | Starboard sidelight | Vessel crossing right-to-left — you are give-way | +| White only (masthead) + green | Overtaking from starboard | Vessel overtaking you on starboard | +| Two white (stacked) + red/green | Two masthead lights | Large ship (≥50 m) underway under power | +| Red + white (all-round, vertical) | Not under command | Give way — vessel cannot maneuver | +| Green + white (all-round, vertical) | Trawler | Give way — engaged in fishing | +| White all-round only | At anchor | Avoid — vessel at anchor | +| White + red all-round (vertical) | Pilot vessel | Pilot boat on duty | + +--- + +## Day Shapes + +| Shape | Meaning | +|---|---| +| ⚫ Black ball | Vessel at anchor | +| 🔻 Black cone (apex down) | Sailing vessel motorsailing | +| ⚫ ⚫ Two balls (vertical) | Not under command | +| ⚫ ◆ ⚫ Ball-diamond-ball | Restricted in ability to maneuver | +| ▬ Black cylinder | Constrained by draft | + +--- + +## Beaufort Wind Scale + +| Force | kt | Description | Sea State | +|---|---|---|---| +| 0 | < 1 | Calm | Mirror smooth | +| 1 | 1–3 | Light air | Ripples | +| 2 | 4–6 | Light breeze | Small wavelets | +| 3 | 7–10 | Gentle breeze | Scattered whitecaps | +| 4 | 11–16 | Moderate breeze | Moderate waves, frequent whitecaps | +| 5 | 17–21 | Fresh breeze | Long waves, many whitecaps, spray | +| 6 | 22–27 | Strong breeze | Large waves, spray, whitecaps everywhere | +| 7 | 28–33 | Near gale | Sea heaping up, foam streaks | +| 8 | 34–40 | Gale | Moderately high waves, edges blowing | +| 9 | 41–47 | Strong gale | High waves, dense foam, visibility affected | +| 10 | 48–55 | Storm | Very high waves, sea white, heavy sea roll | +| 11 | 56–63 | Violent storm | Exceptionally high waves | +| 12 | 64+ | Hurricane force | Air filled with foam, visibility nil | + +--- + +## Common Knots + +**Bowline** — fixed loop that won't slip. The classic sailing knot. "The rabbit comes out of the hole, round the tree, and back down the hole." + +**Cleat hitch** — securing a line to a cleat. Take a round turn around the base, then two figure-8 turns, then one locking hitch over the horn. + +**Clove hitch** — temporary attachment to a post or rail. Two half hitches; easy to adjust and release. + +**Figure-eight** — stopper knot. Prevents a line from running through a block or fairlead. + +**Round turn and two half hitches** — secure, adjustable attachment to a ring or rail. + +**Reef knot** — joining two lines of similar diameter. Right over left, left over right. Not for critical loads — use a sheet bend for mismatched diameters. + +**Sheet bend** — joining two lines of different diameter. The thicker line forms the loop. + +**Rolling hitch** — attaching to another line or spar under load. Grips when pulled along the spar. + +**Anchor hitch (fisherman's bend)** — the correct knot for attaching a line to an anchor. + +--- + +## Buoyage — IALA System B (Americas, Japan, Philippines, Korea) + +**Red right returning** — red buoys on the starboard side when returning from sea. + +| Mark | Shape | Color | Top Mark | Meaning | +|---|---|---|---|---| +| Port lateral | Can / pillar | Red | None | Keep to starboard (IALA-B: keep red to starboard) | +| Starboard lateral | Nun / cone | Green | Cone | Keep to port | +| Safe water | Sphere | Red + white vertical stripes | Sphere | Safe water on all sides | +| Isolated danger | Pillar / spar | Black + red bands | Two black balls | Isolated danger, safe water around it | +| Special mark | Any | Yellow | Yellow X | Special purpose (mooring, racing, TSS) | +| Cardinal (N) | Pillar / spar | Black over yellow | Two cones pointing up | Pass to the north | +| Cardinal (S) | Pillar / spar | Yellow over black | Two cones pointing down | Pass to the south | +| Cardinal (E) | Pillar / spar | Black-yellow-black bands | Cones base-to-base | Pass to the east | +| Cardinal (W) | Pillar / spar | Yellow-black-yellow bands | Cones point-to-point | Pass to the west | + +*IALA-A (Europe, Africa, most of Asia):* Red/green assignments are reversed — "red left returning." + +--- + +## VHF Radio Channels + +| Channel | Use | +|---|---| +| 16 | **International distress, safety, and calling** — always monitor | +| 22A | US Coast Guard working channel | +| 9 | Boater calling channel (US) | +| 6 | Ship-to-ship safety communications | +| 13 | Bridge-to-bridge (1 watt) | +| 70 | DSC digital selective calling — do not use for voice | +| 24, 25, 26, 27, 28 | Public correspondence (marine operator) | + +**MAYDAY procedure:** +1. MAYDAY MAYDAY MAYDAY +2. This is [vessel name × 3] +3. MAYDAY [vessel name] +4. Position +5. Nature of distress +6. Number of persons aboard +7. Any other information +8. Over + +--- + +## Tide and Current Basics + +**Flood** — tide coming in (rising sea level). +**Ebb** — tide going out (falling sea level). +**Slack** — the period of minimal current around high and low water. + +Rule of twelfths — tide rises/falls unevenly: +- Hour 1: 1/12 of range +- Hour 2: 2/12 of range +- Hour 3: 3/12 of range ← fastest +- Hour 4: 3/12 of range ← fastest +- Hour 5: 2/12 of range +- Hour 6: 1/12 of range + +**Spring tides** — larger range; occur near new and full moon. +**Neap tides** — smaller range; occur near quarter moons. + +--- + +## Distress Signals (Rule 37 / SOLAS) + +Any of these signals indicate distress and request assistance: +- Red parachute flare or red hand flare +- Orange smoke signal +- MAYDAY spoken over radio (Ch 16) +- SOS (···−−−···) by any signaling method +- Continuous foghorn sound +- Gun fired at approximately 1-minute intervals +- Flames on the vessel +- Slowly and repeatedly raising and lowering both arms +- Square flag with ball above or below it +- Orange dye in water +- Satellite EPIRB signal |
