Sailing Term Spotlight: The Boom Why It’s Called a Boom – and How to Avoid Hearing It

Sailing Term Spotlight: The Boom
Why It’s Called a Boom – and How to Avoid Hearing It

You don’t have to be long on the water before someone yells, “Mind the boom!” And for good reason.

The boom is the horizontal spar (pole) at the bottom of the mainsail that helps shape and control the sail. It swings from side to side as the boat changes tack — and if you’re not paying attention, it can quite literally boom you on the head.

But why is it called a “boom”?

Like many sailing terms, it has Dutch origins. The word “boom” in Dutch simply means “pole” — but English-speaking sailors quickly appreciated the other meaning too. One unexpected jibe and you’ll understand the onomatopoeia perfectly.

What the Boom Does:

• Holds the bottom of the mainsail tight (like a tensioned sheet)

• Swings with the wind when tacking or gybing

• Allows for better sail shape when on different points of sail

Why It Matters:

• It controls a lot of the sail’s power — and therefore the boat’s speed

• It can be dangerous during an unplanned gybe

• Poor boom handling often leads to capsizes or injury in small dinghies

Avoiding the Boom:

• Keep low when changing sides

• Communicate with your crew when tacking or gybing

• Learn to anticipate wind shifts and boat movement

• Use a boom preventer in bigger boats when running downwind

Whether you’re crewing on an RS Toura or dreaming of an A-Rater, respecting the boom is a rite of passage in sailing. And no, a bump on the head doesn’t count as a proper introduction.

 The Boom is just one of our 80 or so Sailing Terms you need to know, found at  https://pmrsailing.uk/sailing-lessons/sailing-terms-list/Boom.html