We’ve discussed the importance of locking a boat trailer before. Boat trailer security is a big deal. While there are a number of tips and tricks to secure your boat trailer, a boat trailer lock is obviously the best option you have. But just like locking up a bike or even your house, you need to choose wisely. Not all locks are created equally, after all. Some will be more worth your money than others and some may be far more expensive than they need to be. Let’s take a look at some of the best and more reliable locks on the market today.

Proven Coupler Lock

Proven makes what may be the best locks in the business. A Proven lock is like Fort Knox for your trailer and if you’ve ever seen one in action you can believe it. We’re not saying it’s impossible to get past this lock, but we are saying it’s not easy. Not by a long shot.

Made from quarter inch thick steel it offers very few points for a thief to even get to a weak point to try to remove it. A hammer, bolt cutters, even grinders are going to be struggling with this lock. Older versions had a softer aluminum puck lock inside that could be drilled into but the newer ones, with the more colorful pucks, are hardened and extremely tough.

The big downside of these locks is the price. They are hands down far more expensive than any other lock on the market. That said, what is your boat worth to you? If you have a $10,000 boat, then a $300 lock may not be a bad idea at all.

Bolt Off Lock One Key Trailer Lock

You may not have seen Bolt locks before but they deserve recognition. This company has been around for a few years and their products are incredibly tough compared to the competition. The most unique feature is how their key locks work.

Unlike traditional locks that come with a set of precut keys, this works a little differently. You need to buy the lock that matches you brand of truck, as in the vehicle you plan to tow the trailer with. Then, when you get the lock just insert your truck key and turn. The lock is essentially blank before that first use. Once your key is in, the lock maps the key and now that key is the only key that unlocks it. Cool, right? Also makes it less likely for you to lose the key later on.

In terms of toughness, this thing is a little tank. The hardened steel is very hard to cut through and a hammer will take a very long time to break it down. The tumbler sidebar is plated as well and picking this lock is not going to be easy for anyone.

For the price and the security that Bolt offers, it really is a top notch lock. Plus it’s highly visible which makes it a theft deterrent as well. Pound for pound, we think Bolt may be the best lock for your boat trailer on the market.

Shoreline Marine Coupler Lock

Doesn’t look like much, does it? This is by no means the fanciest lock on the list and it’s not the toughest, either. As we keep saying, a determined thief can get the best of any lock. But at the remarkably cheap price, Shoreline Marine has offered up a surprisingly good quality lock.

Shoreline Marine specializes in boats and that’s worth remembering. A lot of the locks out there are made for trailers in general, which is fine. But Shoreline Marine understands the needs of boaters and created a simple and effective lock.

This little lock secures the lever on a hitch in place so that a ball can’t get up under it and a tow vehicle cannot be attached. The key actually screws the locking mechanism into place so you can tighten it up as much as the space you’re dealing with allows.

Once stalled there’s not a lot of wiggle room so getting a grip in the lock to try to remove it isn’t always easy. That said, we’re not trying to trick you here. This lock can definitely be destroyed if someone is persistent enough. We’d recommend this in conjunction with some other methods if you chose to use it. Someone with time and tools could break this off so you don’t want it to be your only security method. But if you’re locking up a trailer for a quick outing, or have it secured in another manner, this is a great option for additional security at a price that literally can’t be beat.

Master Lock Coupler Lock

Master Lock is a recognized name in the world of locks and, by and large, their products are well made and reliable. Their universal trailer coupler lock offers quality security at a good price. The bright red color is a clear indicator to thieves that you have some security measures in place. The lock itself is well made and designed to resist picking and other methods of prying it apart.

The coating will help the lock resist the elements so you don’t need to worry about it being outdoors for long periods. The universal fit means it will likely fit on any trailer you may be using but, as always, check the specs before you make any purchase.

Unlike some companies, Master Lock offers up unique keys which is a great feature. If you and a neighbor both have this lock, your keys will probably not work for one another. As crazy as it sounds, not all trailer locks are made that way. That said, if someone has a few sets of Master Lock keys, they might be able to fall on the right ones here.

We’ve heard these locks may freeze up after a couple of seasons so keep that in mind. Make sure the tumblers are kept clean and use a lock lubricant or other anti-freezing compound if necessary.

Trimax Umax 100 Lock

Hardened steel and ballistic nylon are two of the features of the Trimax Umax worth taking note of. The nylon covered body absorbs hammer blows or other blunt force trauma making it harder to destroy this lock by beating it into submission. The hardened steel locking bar is thick and sturdy so cutting it off will not be an option in most circumstances.

Trimax is so confident in their lock they’re offering you a lifetime guarantee. Right there is why you want to seriously consider this lock. It’s reasonably priced as well, not as low as many but not nearly as high as some, either.

The lock fits from 1-7/8″, 2″, to 2-5/16″ and covers all coupler types. It opens with a 7-pin key lock that is powerfully built to withstand even drilling. The key itself is also tough and you shouldn’t have to worry about it bending or breaking by accident.

Equipment Lock BRHL

This monster of a lock blends form and function quite well. The bright red color is an instant warning to would-be thieves that you’ve installed a lock. That means most thieves won’t even bother to get started. But even if they do the ¼” steel plating will put up a lot of fight to anyone who wants to try cutting it off.

Designed to fit any 1-7/8″, 2″, 2-5/16″ or ring/pintle type hitch, it’s easy to install and comes with two keys. The tubular pin tumbler is harder to pick than some of the cheaper locks out there adding another way to stump thieves in their efforts.

The plate itself is 5 inches by 6 inches. With the bright red color, there’s no way this thing isn’t being seen. It’s hardened steel and coated to resist corrosion as well. Ring or ball, this will fit over either.

On the downside, it does come in a little pricier than some locks. Of course, it’s tough so you’re getting a quality product. In terms of performance, this could give you issues in colder weather. The locking mechanism is known to have icing issues, so if you’re looking to move it in winter, bring some de-icer just in case.

Mophorn Trailer Wheel Lock

When you want the added security of a wheel lock, look for something like the Mophorn wheel lock. There are plenty of pincer-type wheel locks that we think are a bad choice overall. They leave the lugs exposed so a thief could just take the whole wheel right off. This kind, with the plate that covers the lug, makes it much harder to remove the wheel. The heavy duty steel can stand up to abuse and, even armed with a pry bar or a grinder, it’s going to take some work for a thief to get this off. Combined with one of the other locks we’ve recommended you’d have a formidable security system set up.

Let’s Go Aero Silent Hitch Pin Lock

If you want a more discreet lock, then the silent hitch pin from Let’s Go Aero has a lot to offer. In general, we wouldn’t recommend many pin style locks. They are far too easy to break off. Look up some YouTube videos and you may be surprised to see just how vulnerable they are. Thieves can pop a regular pin lock in less than five seconds and that’s not an exaggeration. Where the pin meets the lock is often very narrow and incredible weak.

The silent hitch pin is threaded and screws into a metal block inside the mechanism out of reach of the thieves. This is important because normal pin locks don’t have that. This extra piece prevents leverage from snapping the pin in the lock when something like a pipe is applied externally as thieves are known to do.

That said, a quality saw could still likely get through the pin alone so you want to make sure you’re using this lock in conjunction with others.

Choosing the Best Boat Trailer Locks

If you have purchased a padlock or a bike lock or anything of the sort in the last twenty years you know that quality varies greatly on the market. Too many cheap locks are out there and you need to be wary. A lock is not doing you much good if a thief can cut it with bolt cutters in just a few seconds, or even just pick it with little effort.

One of the biggest problems with choosing a lock is how the market works today. You might see certain locks for sale on Amazon that have hundreds if not thousands of positive reviews and think they work great. But if you check around a little you can also find people on YouTube showing how to disable the same lock in mere seconds. Just because 1000 people had a good experience with a lock doesn’t always mean it’s a good lock. It means no one tried to steal their boat trailer yet. The only true test of a lock as a tool for security is to see how well it holds up to someone who is legitimately trying to steal it.

We can’t guarantee any lock 100%. No one can, really. A thief with the right tools and enough time can probably get through any lock. If you research every single one of the locks we’ve recommended we’re pretty sure you’ll find a review from someone who either broke it off themselves or had one broken by a thief. But here’s the thing – does that make them poor choices? Not necessarily. They say a good lock only keeps honest people honest, but it also slows down the dishonest ones. Having two or more security measures in place maximizes your chances of not being victimized. Just because someone can break a lock doesn’t mean you shouldn’t use locks. Why make it easy for them? All of our recommendations are designed to make stealing your boat trailer as hard as possible. The more you can do to make a thief give up or, even better, not even start to try to steal your boat trailer, the better.

You need a lock that offers real security, so consider some of these features when comparing options.

Types of Boat Trailer Locks

There may be other types of locks on the market but these are the most common and most effective.

Boat Trailer Hitch Lock

Also called boat trailer tongue locks or a trailer coupler lock these locks are very effective if they are made of quality materials. If we had to recommend only one kind of boat trailer lock, this might be it. These work by sitting over the hitch itself. Sometimes there’s a ball that fits into the hitch or coupler and then another part loops over the hitch to secure the whole thing in place. It prevents anyone from hooking your trailer up to a tow vehicle until the lock is removed. If you use a high quality lock of this kind, your trailer will be all but impossible to move.

There are many models of these available and some look like they might be tough but they can be cheaply made. Be wary of ones made of cast aluminum or with loose fitting locking mechanisms. Many of these can be pried loose easily or the locks can be picked with little effort. If your boat is worth thousands of dollars, an off brand lock that was just a few bucks is probably not worth it. Look for a trailer hitch lock made of steel or some alloy that is designed to be tough and durable and resistant to cutting and lock picking.

Wheel Lock

These are like the locks parking enforcement may use around your city. Also known as a boot, these lock in place over a wheel and prevent the trailer from being moved. While these can be effective, they work best as part of a multi-pronged approach to boat trailer security. So use a wheel lock as well as a tongue and hitch lock.

You want a wheel lock that covers the lugs if you choose this route. That may seem obvious but there are some that are not designed that way. That means a thief could just take the wheel off with the lock attached to it and put on a spare or work the lock off and replace the trailer tire when they’re done.

A good quality boot will be forged from strong metal like a steel alloy. It should be able to resist most methods to remove it like sawing or prying with a crowbar. Remember, a bike thief may only spare a few means trying to get a lock off but a boat thief can be a very determined person. They’re trying to steal something potentially worth thousands of dollars, so they may come armed with angle grinders and more.

If you go with a wheel lock, make sure you have your spare tire locked up as well. You wouldn’t be the first boater to lock a wheel only to have a thief remove it and replace it with the spare that was left unsecured.

One of the best options you can go with is to secure the spare elsewhere, or even remove the tire that isn’t locked as well. All of this will take more time and be a little inconvenient, but it’s not as inconvenient as someone stealing your boat.

Pin Lock

Pin locks, sometimes called receiver locks, are very simple and small but a high quality pin lock can be quite effective. Pin locks slide into the tongue part of the trailer and connect the trailer and receiver. You can also use some kinds in the trailer alone to prevent a tow vehicle from attaching, depending on the type or trailer you’re using.

You need to make sure you have a high quality pin lock for these to be effective, as with any lock. We recommend threaded silent pin locks. Silent pin locks are designed to stop that rattling sound you get when towing sometimes. But the right kind adds security. If the lock is threaded and screws into a small steel block inside the hitch itself, that’s the kind you want. Practically, that’s what keeps it from rattling. But for security, it also prevents the pin from being broken off.

Normal pin locks can look very tough and secure, like long steel bars. But if it’s a non-threaded kind, look for the lock mechanism itse;f. The steel is likely very narrow and thin at the point where the pin and lock fasten together. That thin point is very weak. Even though a thief can’t access it directly to cut it, they won’t need to. There are videos that show how, with a simple length of pipe placed over the end of your pin lock from the outside, enough leverage can be applied to snap one of these locks literally in seconds.

A silent lock that is threaded and requires the pin to be screwed into that secure block prevents this from happening. Likewise you can get curved pin locks as well. These pins are angled so that a bar cannot be affixed on the end to give a thief powerful leverage.

Padlock and Chain

Here’s the old standby for any security measure. A padlock and a chain is by no means the best option but it can have a place in boat trailer security. Obviously you’d want a high quality chain that can stand up to bolt cutters. Likewise you’d want a padlock that is hard to cut or pick as well. Why go to all the hassle with all of these other locks? There’s a psychological reason, if nothing else. The other locks we have recommended are often small. Pin locks are almost impossible to see until someone is right up on your trailer trying to steal your boat. But a padlock and chain can be seen at a distance. That’s a warning sign that you have secured your boat. Now, alone, it may not be very effective. A determined thief will not be scared off by any mere chain and padlock. But an opportunistic thief, one just driving by who sees your trailer and thinks maybe they can steal it, might be warned away by a padlock and chain.

It’s also worth noting that, even if a padlock and chain is not super effective, it can be another layer of security. If you have a hitch lock and a padlock and chain, that’s two things a thief has to deal with. That’s more time they need to waste and more chances they’ll fail or get caught. So it’s never a bad idea to use this.

If you do choose to use a padlock and chain, just make sure it’s not by itself as we stated. Also, make sure you have it looped in well. Wrap it through the wheels and around the frame several times to ensure it’s as secure as possible. If you can lock it to a ground anchor, even better.

Other Things to Consider

Now that you know the types, let’s check out some features.


You’ll notice locks, regardless of type, tend to come in either subdued colors or dramatic ones. Many are offered in natural metallic finishes, maybe a shiny chrome, or even black. Others, especially hitch locks, can be bright yellow and orange. There is a practical reason for concerning yourself with the color.

As ugly as some locks may be, they are noticeable and that’s the point. Just like when you put a sign in your window to say you have a guard dog or that your house has a security system, a bright lock sends a message. It’s telling thieves, at a distance, that your trailer is protected. That’s a good thing. If a trailer thief sees your lock from across a lot and realizes it’s not worth the effort, you win. Any opportunity you can get to make someone think twice about stealing your boat trailer, the better. This isn’t to say the metallic or black ones are bad, but they’re just harder to spot. That means a thief may approach your boat trailer and even break out tools before they notice. And even if the lock holds, a potential thief could cause a lot of scratches and dents to your trailer paint, your tow vehicle or the boat itself as they try to steal it.


The fact of the matter is, a lot of locks are cheaply made these days. They use flimsy metal, maybe just cast aluminum, and that doesn’t offer a lot of security. What you want is steel alloy, something strong, rugged, and durable. Something that can’t be broken off with a hammer or bent apart with a crowbar. Keep your eye on those cheaper locks that are just a few bucks, especially if they list only certain parts as being made from steel. A lock bar made of steel isn’t that great if the rest is aluminum. In fact, it may make it easier to break because a thief can hammer on the steel parts to damage the aluminum ones.


Most boat trailer locks use keys, but there are a few combination ones. Key locks are often a better option because they’re more secure. That said, make sure they’re actually more secure. What does that mean? Well, consider something like the very popular Reese Towpower lock. It has over 15,000 reviews on Amazon, and a great overall rating. It’s also bargain basement priced and seems like a great deal, right?

The thing about this lock and other cheap ones is that the keys are machined en masse. That means every lock uses the same keys. A thief can buy this lock and now he has access to the locks of 15,000 satisfied Amazon customers. That’s not a good thing. And the keys also have a habit of breaking in the lock, so that’s another risk factor. Well made, well-designed keys are important.

Look for high quality keys that are unique to your specific lock.


Not every lock fits every trailer and that can cause issues. Make sure you review all the technical specs before making a purchase. When shopping online this gets even more important because most of us have had at least one experience with an online purchase that turned out to be the wrong shape or size when it arrived.

Couples tend to come in three sizes – 48, 51, and 59mm. Make sure you know what size you’re dealing with if that’s the kind of lock you want. Likewise, if you go for a wheel lock, ensure it’s designed for the size of the wheel on your trailer to avoid having the hassle of sending it back again.


One of the big issues people have with boat trailer security is the perceived effort. And we get it. Taking all this time to lock up wheels, affix couplers, loop a chain and padlock. It can become a chore. Often you just want to drop the trailer and go. An easy to use lock is a great benefit for that reason. Some locks are incredibly easy to use while others are weirdly complicated. If you’re not sure, check the reviews to see how other boaters have found them. You don’t want to be fumbling 10 pieces of a lock if you don’t need to be. The faster and more efficient, the better.


Any product that comes with a warranty is superior to those that don’t. But do make sure you check out the warranty with your lock. Some companies offer pretty wishy washy warranties that only last a few months, or only cover very limited circumstances.

Top quality lock makers stand behind their locks. They’ll offer warranties that cover years or even lifetime warranties. At the very least you want a warranty that covers problems with workmanship. That means if the manufacturer messed up, they’ll replace the lock for you.


This is where buying a boat trailer lock becomes a balancing act. You can find some that cost under $20 on Amazon right now. Then there’s our premium choice, the Proven lock, which is around $300. That’s a very big range but it’s a serious consideration and we’ve detailed some of the reasons already.

Cheap locks are often made of cheap materials. That’s not to say the Proven lock is, hands down, the best made lock ever, but it does work and it works well. If you have a $15,000 boat on your trailer, do you trust the $20 lock manufacturer by a company you’ve never heard of? Or do you want to go with a lock that comes with a warranty, is made in America, and has customer service you can easily contact? Sometimes you need to pay a little extra to make sure something works but it all depends on your needs and what you think works best. We have a range of reliable options here for just that reason.

How Strong is a Boat Trailer Lock?

A common criticism you’ll see in trailer lock reviews is just how easy and fast it is to break that lock. If you watch some videos it might blow your mind. Some locks, quality ones at that, can be taken off in literal seconds. So how can they be considered good locks?

Well, to start, when you see a lock get taken out really quickly it was by someone who really prepared. A sledge hammer or an angle grinder isn’t the kind of thing any random person walks down the street with. So these people are trying to steal your trailer and they came prepared. And the fact is we make tools to cut and break things for legitimate reasons because we need them in real life. It’s just that thieves misappropriate them sometimes and it’s hard to make something that can stand up to that for a long while. Even the best lock is likely to fall after a couple minutes of work.

Every second counts when someone is trying to steal something like your boat trailer. So, again, the harder it is to do, the better. Start with a couple of locks and then consider enhanced security. That can include how you park your tow vehicle to make removing the trailer all but impossible to do without moving the truck as well. Motion sensors and alarms are also great supplemental security measures. When you have several things working together, your boat trailer stays safer longer.

The Bottom Line

It is almost impossible to make something 100% unstealable. Cars are stolen every day even with top notch anti-theft features, even banks get robbed. What we can do is try to lower the probability that it will happen. Be smart with where you leave your boat trailer and how you secure it. Use multiple lock types and try to make use of alternate security measures as well. Make sure you remove valuables from your boat and keep the boat and your trailer ensured.