How To Raise the Boom on a Sailboat in 5 Easy Steps

On this page:

1. Why Would You Want To Raise Your Boom
2. How To In Five Steps
3. What If I Am Now Discouraged?
4. In Conclusion

Why Would You Want To Raise Your Boom

You might ask why even go down this path. After all, sailboats are made by experts who know what they are doing, and a boom is precisely where it is for a good reason.

Well, not so fast. Say your sailboat doesn't have a boom vang because it is more of a leisure cruiser. But you have adventurous blood coursing through your veins, and you want to add that boom vang to your vessel. So you do your research, you do all the measurements, and oops, the boom is too low for a standard vang.

This specifically is why quite a number of 30-foot C&C owners were looking precisely into this topic.

Or say you want to add a bimini to the cockpit for that extra shade and comfort, but the low placed boom doesn't allow for this.

Or what if safety is your concern? Especially on smaller sailboats, the boom can be placed so low and extend so far into the cockpit that chances of somebody's head getting injured when the boom swings are high.

All in all, there are reasons to look into it. As is the case with any other vehicle, although they do come from the store ready to rock'n'roll, there are often ways to tinker your way to improvement in case the product doesn't fit your needs. The car tuning scene could write a book on the topic.

How To In Five Steps

Firstly, let's talk about how to go about raising the boom. Though the oftentimes confusing sailing terminology glossary is a thick book already, we have to introduce yet another new term - gooseneck. It is a bunch of parts that connect the boom to the mast.

1. Drilling New Holes

The gooseneck is attached to the mast with rivets or screws, so it is possible to change its position by simply drilling new holes in the desired height. Do this carefully though. There are incredible forces exerted on a mast when under sail and you don't want to compromise its rigidity.

Easy, right? This main part is not that tricky, and anyone with enough prudence and diligence can do it without the need to even use any specialized equipment. Unfortunately, you're not even halfway done.

2. Filling The Old Holes

Let's get back to the rigidity issue. You have drilled your holes, maybe even repositioned the mast already. Now there are a few extra holes in your mast, which is not good news for its strength. You have to fill them to make sure the mast can still take the load, which is easily done with short rivets or something of that sort.

So again, nothing technically difficult with a bit of love and care. But it is a step you don't want to overlook as if you do, your mast will be more likely to snap in half when the wind hits the sails.

3. Shortening The Sail

Now come the tricky steps. The precise position of a boom is not a standalone matter, rather it is influenced by and influences quite a few other aspects and parts on your boat.

One of these is your sail size. As you might have expected, raising a boom changes the sail area of your mainsail, so you need to resize it. Regardless of if your sail twists inside of your boom, mast or simply rests on the boom, this needs to be done.

Unfortunately, unlike the previous steps, this is not a DIY project for most. You can't simply cut off the extra part, because, for instance, the seams have a specific curvature. If you ignore this, your performance will decrease significantly as you will mess up the sail shape. This won't be that noticeable when you go downwind, but when sailing upwind you will notice the difference. Which means you might need to leave this in the hands of a professional sailmaker.

Also, because you will most likely be cutting the sail at the bottom, you will need to redo the two corner reinforcements too. And since the prudent thing to do here would be cutting the sail from the bottom as well as the back so that the shape is maintained, in case you have battens in your sail, you will need to adjust them and the pockets they sit in.

It sounds like a lot, I know. This is why you might conclude that getting an entirely new mainsail might be less of a hassle and cheaper than redoing your old one, especially if it has been used for a while already.

4. Making Sure The Boom Doesn't Interfere With The Backstay

Another of the parts that might be influenced by your tinkering is the backstay. Since it goes from the back of the boat to the top of the mast, if you put your boom up, its backside might collide with it.

Repositioning the backstay is unrealistic, and so you might find yourself having to shorten the boom too. I know we are getting quite far from the original simple task of just raising the boom, but rigging parts are in a delicate unison and tweaking one tends to require you to tweak the others too.

Gosh, I sure hope you read this whole thing before drilling the holes.

5. Checking The New Position's Functionality And Compatibility

I don't mean to discourage you from raising your booms, but I have yet another bit of news that might make some of you turn back on this project.

As expressed above, many things on a sailboat are intertwined. So even if you successfully raised the boom, reshaped your sail, or ordered a new one and made sure the boom doesn't collide with the backstay, you still gotta check if everything else works as it should.

One such thing might be the boom vang - as it is directly attached to the boom, you might need to swap it for a different sized one and also adjust the line length.

The same goes for all the other lines - if the boom is now set higher, better make sure you have enough ropes to work with. This probably won't be an issue since the change is not that drastic but better safe than sorry.

All in all, make sure you test the rigging properly, simulate various potential situations so that you are sure the new boom position doesn't interfere with stuff it shouldn't interfere with.

What If I Am Now Discouraged?

Great question. If you expected a reliable how-to guide, but instead this article stabbed your tinkering enthusiasm in the back with a long list of all the inevitable negatives, consider this mighty plan B.

If the goal is to get the boom out of the cockpit (and in most instances, this will be the case), there is a possible alternative that requires little in terms of effort, at least compared to the original plan. And you won't even need a screwdriver.

Here is what you can do - simply raise the end of the boom enough to have it be well above the cockpit area. Yes, that means raising it a lot - enough to require altering the sail shape. But that will be the only demanding thing you will have to do, regardless of whether you want to try to reshape the sail yourself (not recommended) or buy a new one.

Cost of Replacing Sails

To get a quick grasp on whether the light is worth the candle, you can check the cost of replacing sails here.

You can try this safely by tightening your topping lift as much as needed to achieve your desired angle, and you will see if it is enough to get you the desired result.

In Conclusion

I apologize. I try to encourage sailing-related ideas and figuring out how to realize them, but contrary to what this might seem like at first glance, raising a boom is no simple task since you have to consider the sensitivity of the rigging orchestra. That being said, even though it is not a DIY project and takes more than a weekend of work, it can be done. So if you are up for it, go for it.