The Solent is home to 157 racing marks managed by the Solent Cruising and Racing Association (SCRA). To race confidently in these waters you need to recognise each mark type on sight — and that’s exactly what Guess the Mark is designed to train. This guide explains the mark types, how the game works, and how to get up to speed quickly.
1. Understanding the marks
All marks in UK waters follow the IALA Maritime Buoyage System (Region A). There are five main categories. The icons below are identical to those shown in the game.
Lateral marks
Lateral marks define safe channels. In Region A, red marks are on the port (left) side when entering harbour; green marks are on the starboard (right) side.
Red cylindrical buoy. Leave to port (your left) when entering harbour or proceeding upstream. Pass it on your left, keeping it between you and the port-side hazard.
Green cylindrical buoy. Leave to starboard (your right) when entering harbour or proceeding upstream. Pass it on your right.
Cardinal marks
Cardinal marks use black and yellow horizontal bands to indicate which direction has safe water. The name of each mark (north, south, east, west) tells you the safe side to pass on. Learn the band pattern and you can read any cardinal mark instantly.
Memory aid: For North and South cardinals, the black band is always nearest to that pole — black on top for North, black on bottom for South. For East and West, remember the shape: East (BYB) has black squeezing a yellow centre like a rising sun; West (YBY) has black in the middle like an hourglass.
Safe water is to the north. Black band on top points towards the North Pole.
Safe water is to the south. Black band on bottom points towards the South Pole.
Safe water is to the east. Yellow band trapped in the centre — like a sunrise breaking through.
Safe water is to the west. Black band in the middle forms an hourglass shape.
Safe water marks
Red and white vertical stripes. Indicates open, navigable water all around — no hazard nearby. Can be passed on either side. Often marks the centre of a channel or a fairway approach.
Special marks
Yellow buoy. Used for special purposes not covered by the other categories — most commonly racing marks. The vast majority of Solent racing marks are special marks. They are not navigation hazards; racers round them as instructed by the sailing instructions.
Blue cylindrical buoy. Appears for a small number of marks in the game dataset. Treat as a lateral mark for navigation purposes.
2. How the game works
Each round you are shown a racing mark highlighted on an interactive map with nearby context marks visible. Choose the correct name from the options given before the timer runs out. The faster you answer, the higher your score.
Difficulty levels
| Difficulty | Time limit | Mark pool | Multiplier |
|---|---|---|---|
| Beginner | 30 s | Famous landmarks without sponsors — towers, forts, lighthouses, banks, and ledges | ×1 |
| Intermediate | 20 s | Sponsored marks, buoys, elbows, and headlands | ×1.5 |
| Advanced | 10 s | All 157 Solent marks | ×2 |
Scoring
Every correct answer earns a base of 100 points plus a time bonus for answering quickly. The total is then multiplied by the difficulty multiplier.
| Difficulty | Max time bonus | Multiplier | Max score per question |
|---|---|---|---|
| Beginner | +30 | ×1 | 130 |
| Intermediate | +50 | ×1.5 | 225 |
| Advanced | +70 | ×2 | 340 |
Streak bonus: Answer 3 or more marks correctly in a row to earn a streak bonus. The bonus is 10 × your current streak length, capped at 100 bonus points per answer. A streak of 3 earns +30; a streak of 10 or more earns the maximum +100.
Special modes
Restricts the mark pool to those within 5 km of Cowes harbour centre — the busiest racing waters in the Solent. A focused challenge for Cowes regulars or anyone preparing for Cowes Week.
Enable this option to see the sponsor name as a clue for sponsored marks. Useful when you’re starting out and the sponsor is a familiar local name.
3. Tips for learning the Solent marks
- Start with beginner mode — landmarks first Forts, towers, lighthouses, and named banks are fixed geographical references that do not change with sponsors. Learning Horse Sand Fort, No Man’s Land Fort, and the shipping channel banks gives you a reliable mental map before tackling sponsored marks.
- Learn by area, not by number Group marks mentally by the waters you know: Southampton Water, the Lymington River, the Hamble, Chichester Harbour approaches. Once you have a cluster of marks in one area nailed, move to the next. The game’s map always shows nearby context marks so you can orient yourself geographically.
- Enable the nautical chart layer Switching on the OpenSeaMap overlay shows depth contours, shoal areas, and channel markers. Cross-referencing the racing mark against a depth feature or a shipping lane often gives a powerful positional clue.
- Check the 2026 changes before racing 23 marks were renamed between 2025 and 2026, mostly due to sponsor changes. If you raced last season, some familiar names will have changed. See the 2026 mark changes page for the full list.
Ready to test yourself?
Put your knowledge to the test on all 157 Solent marks — from Beginner to Advanced. How many can you name?
Play Guess the Mark →