Boat Flag Guide: Flag Types, Sizes, and Mounting

Most new boaters run into the same problem; they don't know what boat flag to fly.

"Boat flag" covers a few different things: your country's flag, a club flag, a signal flag, and novelty flags. This guide sorts out which one you need, where it belongs on your boat, and what size fits.

Types of Boat Flags

Four main categories exist. Pick yours based on what you want the flag to say: your nationality, your club, a maritime signal, or your own style.

Don't see a burgee or signal flag on our site? We don't carry those as stock items — our custom flag team builds them to your club's or vessel's exact spec. Explore custom flags.

One more term worth knowing: a courtesy flag is a small flag of a host country's colors. Boaters fly this when visiting another country by water, alongside their own national ensign, not instead of it.

Where Every Flag Belongs

Every flag above belongs somewhere and it's part of what the flag communicates. A club burgee flying from the wrong place doesn't just look off, it stops saying what it's supposed to say. Here's where each one goes, and why.

Three rules sit underneath that table:

The ensign doesn't move. It stays at the stern no matter what else you're flying. It's also the one boat flag governed by law — only the correct national ensign may fly in that position — so it never competes for space with anything else. Fly it roughly sunrise to sunset and check local practice if you're unsure.

The burgee's position depends on your rig. Traditionally it flies from the bow staff on a single-masted powerboat, the foremost masthead on a schooner or multi-masted powerboat, or the main masthead on other rigs. Most boaters fly it lower in practice — at the end of the lowest starboard spreader — because starboard has been the position of honor in flag etiquette for as long as boats have carried more than one flag. Some clubs set their own convention, so check yours if you're unsure.

Starboard is reserved for whichever flag outranks the others. That's why a courtesy flag also claims the starboard spreader when you're visiting another country's waters — see the tip below for what that means if a burgee is already there.

What Size Boat Flag Do You Need?

Two measurements matter here: the hoist (the short edge that attaches to the pole) and the fly (the long edge that stretches out). Boat-length guidance below uses fly length.

A small flag disappears against the horizon. A big one strains the pole and hardware. Start with your boat length, then adjust for space and hardware limits.

A common rule: about one inch of fly for each foot of boat length. A 30-foot boat pairs with a flag near 30 inches, such as 20 x 30 inches. Treat this as a guide, not a fixed rule.

Pick a pole about twice the length of your flag's hoist. An 18-inch hoist pairs with a pole near 36 inches. Browse flagpoles and hardware to find the right fit for your mount.

For the 40-foot row: pick the smaller size if space is tight or your pole is shorter. Pick the larger size only if your pole and hardware are rated to handle it.

How to Mount Flags Correctly

Once you know where a flag belongs, here's what holds it there. On every boat type, keep the flag clear of the exhaust, lights, rigging, passengers, and moving parts.

Powerboats

Mount the flag on a pole at the stern (transom), using a flagpole socket, a pole, and side clips or a ratchet-style clamp. A through-bolted socket with a backing plate holds up best if the mount is staying put; stainless steel or anodized aluminum hardware resists salt corrosion far longer than plain steel. If you'd rather not drill, a clamp-on transom socket is fully removable and works well for boats that get trailered or stored between trips. Keep the pole clear of the engine exhaust and any rear-facing lights — heat and soot wear a flag out faster than wind does.

Sailboats

Sailboats usually mount the ensign at the stern too, on a staff angled to clear the backstay. Underway, some boats fly it from the backstay itself instead, especially when the stern rail isn't a clean fit. Signal flags and the burgee run on their own thin halyards along the rigging, separate from the ensign's line, so each flag can be raised, lowered, or swapped without disturbing the others.

Small Boats and PWCs

Smaller boats often use a rail clamp or a low bracket instead of a stern socket. Since there's less distance between the flag and the rider, motor, and any towed gear, keep the pole short and mounted low enough that the flag can't reach a rider's sightline or a tow rope. A flexible or spring-loaded pole holds up better against wake and dock bumps than a rigid one.

Before you drill: check the mount angle, backing support, pole width, fastener type, and clearance from engine covers, rails, and moving parts. Ask your club, marina, or hardware maker if you're unsure.

Insider tip: A swivel-style mount lets the flag rotate with the wind instead of wrapping tightly around the pole. That single change does more to prevent fraying than any fabric choice — see our American Flag Fading and Fraying Guide for the rest of what causes wear.

Choose an outdoor American flag sized for your boat and mount.

Can You Fly a Pirate Flag on a Boat?

Yes, most boaters treat pirate flags as novelty flags. Rules vary by marina, club, and location, so check locally before flying one.

Keep it clear of lights, registration markings, safety gear, and anything used for required signals. Some marinas and clubs set their own rules on top of this. Placement rules don't disappear just because a flag is for fun — a novelty flag still needs its own clear spot, not squeezed in wherever there's room.

How to Care for a Boat Flag

Where a flag lives affects how long it lasts, too. Salt, sun, wind, and moisture wear flags down faster on the water than on land. Cleaning and checking your flag regularly cuts down on early fading and damage.

After saltwater exposure, rinse the flag with fresh water. Let it dry fully before storing to avoid mildew and odor.

Check the fly end, seams, header, grommets, and hardware every few weeks and after strong wind. Look for fraying, corrosion, loose stitching, and fading. Replace the flag once fraying spreads or fading gets bad and retire worn U.S. flags respectfully.

For a full checklist on spotting wear and deciding repair versus replace, see our American Flag Fading and Fraying Guide. Boat flags wear out faster than home flagpole flags, so check yours more often.

Frequently Asked Questions

Can I fly more than one flag on my boat?

Yes — each one has its own spot. The national ensign flies at the stern, a club burgee at the bow staff or starboard spreader, and a courtesy flag at the starboard spreader when you're visiting another country's waters, taking that spot over the burgee, which shifts to port for the trip. See Where Every Flag Belongs above for the full breakdown.

Which side does the courtesy flag go on?

Starboard. The courtesy flag represents your host country's waters, which outranks club identity — so if a burgee is already on that spreader, move it to port for the trip.

Where does a yacht club burgee fly?

Traditionally from the bow staff on a single-masted powerboat, the foremost masthead on a schooner or multi-masted powerboat, or the main masthead on other rigs. In practice, most boaters fly it lower, at the starboard spreader — unless a courtesy flag is already there, in which case it moves to port. Check your club's own guidance; some set their own convention. Need a burgee made? Our custom flag team builds them to your club's exact spec — explore custom flags.

What is the standard size for a boat flag?

About one inch of fly per foot of boat length, with a pole roughly twice the flag's hoist. Confirm the fit against your mount before you order.

What is a flag on a boat called?

A boat's national flag is called an ensign. A club flag is a burgee. Decorative flags go by novelty or display flags.