How to Use a Hand Bearing Compass at Sea
A bearing compass is one of the most useful tools on the water — and one of the least understood. Here's how to use it correctly, when it matters most, and what to look for when buying one.
What Is a Hand Bearing Compass?
A hand bearing compass is a portable magnetic compass used to take directional bearings on objects — a mark, another boat, a lighthouse, or a hazard. Unlike a fixed steering compass, you hold it up to your eye or in your palm and read the bearing to whatever you're looking at.
In sailing, it's most commonly used to check whether you're on a lifted or headed tack, to take bearings on marks before and during a race, and for general navigation when GPS isn't available or reliable.
How to Take a Bearing: Step by Step
Step 1 – Hold the Compass Steady
Hold the compass with both hands at eye level. Keep your elbows tucked close to your body. On a moving boat, brace against the mast, shroud, or coaming for stability.
Step 2 – Aim at Your Target
Look through the sighting window or across the compass face at the object — a mark, a headland, or another vessel. Most hand bearing compasses have a prism or sighting line that lets you read the bearing while looking at the target at the same time.
Step 3 – Read the Bearing
When the compass card settles, read the number aligned with the sighting line. This is your magnetic bearing in degrees (0–360°). Take 2–3 readings and average them if the boat is moving significantly.
Step 4 – Record or Compare
Take a second bearing to the same object a few minutes later. If the bearing has increased, you're lifted. If it's decreased, you're headed. This is race-winning information.
When Sailors Actually Use a Bearing Compass
Checking Wind Shifts
Take a bearing to the windward mark at regular intervals. A consistent shift tells you which side of the course is favoured.
Collision Avoidance
A constant bearing to an approaching vessel means you're on a collision course. Take three bearings 30 seconds apart — if it doesn't change, act immediately.
Setting the Start Line
Race officers use a bearing compass to check the angle of the start line relative to wind direction. A bearing compass is the fastest way to verify a square line before the sequence begins.
Piloting and Navigation
Taking bearings on fixed landmarks lets you plot your position without GPS. Two intersecting bearings give you a fix.
What to Look for in a Hand Bearing Compass
| Feature | Why It Matters |
|---|---|
| Waterproof construction | Salt spray and rain are constants at sea. A non-waterproof compass will fog, corrode, and fail. |
| Damped card movement | A liquid-filled compass settles faster on a moving boat. Faster settling = faster readings. |
| Clear degree markings | Readings in 2° or 5° increments are readable under pressure. |
| Lanyard attachment | A compass dropped overboard is useless. A lanyard keeps it on your wrist. |
| Comfortable grip | You're taking readings with one hand on a moving deck. |
Common Mistakes
Taking readings near metal. Winches and stanchions deflect magnetic north. Step away from metal structures before taking a bearing.
Not waiting for the card to settle. Rushing a reading on a moving boat gives you a number, not a bearing.
Ignoring variation and deviation. Magnetic north isn't true north. Your chart will show local variation.
Frequently Asked Questions
What is a hand bearing compass used for in sailing?
A hand bearing compass is used to take directional bearings on marks, hazards, and vessels. Sailors use it to detect wind shifts, check collision risk, set start lines, and navigate in coastal waters.
What is the difference between a steering compass and a hand bearing compass?
A steering compass is fixed to the boat for helming. A hand bearing compass is portable and used to take bearings on external objects.
How accurate is a hand bearing compass?
A quality liquid-damped hand bearing compass is accurate to within 1–2 degrees in steady conditions. On a moving boat, expect 2–5 degrees — still more than enough for tactical decisions.
Do I need a compass if I have GPS?
Yes. GPS tells you where you are. A compass tells you the bearing to a specific object right now — useful for collision avoidance, wind shift detection, and when GPS fails.
The Bottom Line
A hand bearing compass pays for itself the first time you use it to catch a wind shift before your competitor does. Learn to use it, keep it on you, and it will be one of the most-reached-for pieces of kit on your boat.
