Most of us probably spend a lot of time riding our personal watercraft near our homes or maybe only a short drive away to a lake or river. A lot of watercraft launch ramps are on rural roads with lower speed limits than the interstate. Others like me may keep jet skis on a floating dock at a marina. But what if you want to head out to a different lake for a change in surroundings?
Jet ski trailers with proper tires can be towed up to 75 to 80 mph. Most newer and well-maintained older jet ski trailers can handle speeds of at least 65 mph with the correct tires without any risks or problems.
Some states in the US don’t restrict jet ski trailers speeds to the posted truck and large commercial trailer speed limits, but it never hurts to check. This list from AAA is typically applied to larger trucks, but a few areas specify weight limits for the laws.
Before you head out
This isn’t a blanket endorsement to just head out at 65-70 mph without doing some inspection and prep work first. Older trailers may need to be driven differently. Always check tire speed rating, which is different than load rating. It’s right on your sidewall. You may have to cross-check a letter with ST trailer tire chart, which is different than passenger car and light truck ratings. (Source Tire Rack)
In order to tow at highway speeds, there are several things to take into consideration or do before heading out.
- Inspect your tires for wear and age
- Check the exact top speed rating for your tires
- Set your tires to maximum recommended pressure
- Check to make sure you aren’t exceeding the tire load rating
- Position your maximum load weight over the axle
- Inspect all components of the trailer coupler
- Inspect the tow vehicle hitch integrity
- Inspect the trailer wiring and lights
- Inspect and replace front and rear straps if needed
- Check the jet ski front strap tower for loosening
- Make sure safety chains are still in good shape
- Keep up with wheel bearing maintenance if this applies to your trailer
- Check and tighten all runners, brackets and mounts
- Regularly check all weld points on the trailer
- Keep your tow vehicle in good condition
- Make sure the driver knows how to handle a trailer. Practice if necessary until you are proficient.
- Carry spare tires and hitch parts to prepare for the unexpected
Let’s go over some of those details to make sure you can tow at highway speed safely without risking an accident, property damage or even serious injury.
Regular Trailer Inspections
Jet skiing is an equipment-oriented activity. All PWC owners know they need to winterize their skis for storage, how to prepare them for summer use, and how to follow maintenance schedules for performance and longevity.
But some may not know you need to take the same care with your jet ski trailer. Although it doesn’t have a motor that needs regular maintenance, there are parts that need to be regularly inspected, and repaired or replaced as needed.
Using your trailer regularly while neglecting to address maintenance can lead to sudden failure of tires, axles, springs, hitches, straps and even the frame. in order to safely tow your jet ski(s) at interstate speeds, you must make sure everything is in proper working order.
Tires: it all comes down to the tires.
When towing any type of trailer, everything hinges on the condition of the tires. Old worn tires with uneven tread or deteriorated rubber are usually easy to spot with a good visual inspection. But what you might not know is that even tires with good tread remaining will gradually deteriorate in long-term storage. This occurs slower indoors and faster when trailers are stored outside.
Factors that increase deterioration of tire rubber include sunlight, extreme hot or cold temperatures and high humidity. So if possible, store your ski and trailer in a climate controlled dry garage or shaded awning. (Source)
If you have a five or six year old trailer with only a few thousand miles on the trailer, the tires have aged just from setting around. Manufacturers recommend replacing tires at 6 years even if they have low mileage to prevent sudden failure or even explosion. Road and Track magazine states that stored unused tires, such as spares, can last as long as 10 years if proper care is taken.
Jet ski trailer tires aren’t very expensive, so this is a fairly easy recommendation to follow. As someone who has been stranded over 100 miles from home late on a Friday evening due to racing trailer tire failures (double axle, 2 flats, one spare), I strongly suggest regular inspection and replacement at 5 years. Buying online will often be cheaper as long as you have a local shop willing to mount them for you and properly dispose of the old ones.
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Always carry a spare wheel and tire
While on the subject of tires, always travel with a spare wheel and tire. You can buy brackets to mount one on your trailer, like shown above, or you can store one in the back of your truck, SUV or car’s trunk. I just ordered the one above for my trailer after years of hauling spares in my truck. My SeaRay trailer has a welded mount, but Triton did not include one on the PWC trailer.
I’ve had a few tire punctures on boat and racing trailers during long trips, and spares have saved me from ruining trips (except for the double blowout in last paragraph.) Marine Products carries several to match different trailers.
I carry 2 spares for my jet ski trailer since they are inexpensive and because of my previous experiences in the last paragraph. I also carry a portable 12V air compressor with a built-in gauge and light. Sometimes you have to park in gravel lots or on the unpaved areas around ramps. Picking up a nail or metal part in your tire can ruin the trip home.
I’ve written about towing your jet skis on long distance trips. On this type of towing, I firmly believe 2 spares is the way to go. And if you end up changing a tire, you can have it replaced or repaired before you head home.
Tire pressure and load ratings
Always check your cold tire pressures before heading out on any trip. Don’t rely on checking them after driving, as the pressure increases during use. Check and adjust after trailer has been setting for at least an hour. Longer if possible. Also keep in mind that tire pressures change 1 psi for every 10 degrees Fahrenheit of ambient temperature change. So if you set your tires in the spring when it was 50 degrees, and then you take a trip in the 90 degree summer heat, the pressure will start out 4 psi higher. Recheck when ambient temperatures change dramatically either direction to avoid problems.
Every tire will have its load rating and maximum pressure stamped on the sidewall. Your maximum allowed load will be the maximum for each tire multiplied by the number of tires, usually 2 since jet ski trailers are single axle. Estimate the weight of your jet ski with fuel and accessories, and compare that to the combined weight ratings of both tires.
If you are near the top range of the tire weight ratings, run them at the top end of the pressure stated on the side wall. A side note to remember when buying tires is that trailer tires will be labeled with ST on the sidewall specifying they were built for trailering with a different sidewall structure to handle the difference in load compared to car tires. So when you buy new tires, make sure to look at your old ones and get the same or higher load and speed rating in an ST tire.
For example, if your dual trailer and 2 skis weigh a combined 2100 lbs and each tire is rated to carry 1360 lbs, you can haul a maximum of 2720 lbs. So the load is within the tire’s specified load range. Refer to the sidewall of the tire for the maximum load at the pressure at which this can be carried. Never exceed the maximum pressure stamped on the sidewall.
Single jet ski trailers will have different tires with a lower load rating. As I mentioned above, I carry this 12V portable air compressor (from Amazon) with me at all times. It has a digital preset gauge with auto shutoff and a light. Both features have come in handy on a few occasions.
Tire Speed Rating
Be sure to look at the speed rating of your tires, as well. A lot of boat and jet ski trailer tires are rated to a maximum of 65 mph (source.) Some are rated to 75 mph, and there are tires available rated to 81 mph. Never exceed the maximum speed for more than a few seconds. While there is a little safety tolerance built in to the ratings, running at excess speeds results in increasing heat build up and rising tire pressures. All of that an contribute to a sudden blowout of a tire, and the result can be a loss of control of the trailer.
Depending on your tow vehicle, a sudden blowout could cause an abrupt change in handling and result in a crash. Even if this doesn’t happen, tire blowouts can damage the trailer, the jet ski, and any nearby cars. Keep your maximum speeds within the tire’s rating.
Trailer coupler inspection
Inspect the trailer’s coupler clamp for loosening every time you hitch to your tow vehicle. This is the bracket on the trailer that swings under the ball to clamp the trailer to the ball. The large nut securing the clamp can gradually loosen, allowing for some hitch movement when connected. Get low and visually check it. Then once clamped in place, lift up and down to make sure the coupling is tight. If loose enough, the hitch can actually jump out of the bracket.
Always have two properly connected safety chains on your trailer. When connecting to your tow vehicle, cross the chains under the hitch for maximum safety. Inspect the chains regularly for weakening or broken links. The chains are bolted to the trailer. At the first sign of a problem, replace the chain with a new one.
If you tow often enough and for a long number of years, you’re bound to experience some type of hitch failure. Maybe a fatigued hitch clamp breaks. Maybe the safety pin didn’t get fully clamped. Maybe you just misaligned the hitch in a hurry in a rainstorm. That’s why trailers have safety chains. Follow all safety guidelines, but be prepared for the unexpected.
Front jet ski winch and braces
Each time you unload and reload your ski, take a quick look at the winch, hook and straps. Make sure the strap isn’t frayed or cut. Make sure the rotating mechanism doesn’t have any play or loosening as you wind your strap. Watch for any rocking of the winch tower as well. Most supports are adjustable and bolted on with brackets. These need to be checked for bolt tightness regularly.
Make sure that the winch suspension post hasn’t moved out of position. You can mark your trailer with tape or a laundry marker once the ski is in proper position. Then each time you go out, just make sure the tower hasn’t moved forwards or backwards. Most of the weight of a jet ski is centered at the engine, and any load on a trailer should have the greatest weight centered over the axle.
Any shift forwards or backwards can alter the handling, and maybe even cause fishtailing with sudden direction changes. Make sure it is set right at the beginning, and check for any changes every time you head out.
I recommend that you put a wrench on the bolts and tighten at the end of each season before storing your jet ski, and once or twice more during your seasonal use. If you live somewhere that provides weather for year-round use, check the bolt tightness 3-4 times per year.
And of course, always be sure to secure the ski properly on the trailer.
Jet ski support runners
When you bought your jet ski, the trailer may have been part of the deal. In that case, the dealer adjusted the position of the hitch support and the width and angle of the underside runners to fit your ski. A lot of first-time buyers don’t know those are adjustable and held in place with bolts just like the hitch tower. Grab a wrench and tighten them a few times each year.
If you find they are already loose, look at how the ski is setting on them. If it looks in good position and they haven’t widened to the point of allowing the ski to drop in the center, just re-tighten them. If the weight of the ski has pushed them further apart, you will have to loosen the mounts and adjust.
To do this, you have to move the ski to a stand, lift it with a hoist, or adjust it at a launch ramp. Boating etiquette requires that you should only do this at the ramp if there is no one else waiting to launch. Loosen the bolts, push the runners in or out until they line up with the correct portion of your hull, keeping the front and rear the same distance apart. Then tighten them back down.
Your trailer may have come with built-in rear ratchet straps, or you may be using separate straps. Either way, pull the strap out of the spool a few times per year and inspect for wear or cuts. When towing, carry two spares with you in case of failure or loss. If using separate straps, you can accidentally lose one in the water or on the road if not fully tightened.
When loading the ski, tighten the rear straps so that the ski doesn’t bounce around on the trailer. You don’t need to squeeze that last possible ratchet position, just get them fairly tight. The front hook and strap does most of the work keeping the ski from moving backwards, the rear straps keep the ski from bouncing around.
Inspect the frame
Check all welds for cracks. Check all bolted frame connections for loosening. Do this 3-4 times per season. If your trailer is aluminum or painted, repairing welds will ge a little harder or costlier.
Some trailers will have sealed bearings that don’t need to be replaced regularly. Older trailers should have their axle bearings inspected once or twice per year. A few references suggest every 10,000 miles (source.) But jet ski and boat trailers may not see that kind of mileage even after a few years. And stored trailers can experience bearing grease drying out when setting around unused.
Replacement recommendations are almost as varied as there are trailer brands. Ask your trailer dealer or check the website if you bought used.
Jack the trailer so the wheels are off the ground. Support it with jack stands. Once it is stable, grab each wheel on the sides and try to rock it back and forth. Do the same by grabbing the top and bottom. If there isn’t any movement and you have bearings that require service, remove the wheel, grease the bearings and put the wheel back on.
If you need to replace bearings, consult a manual, find instructions online or have a shop do it. The job isn’t difficult, but you may need a special bearing ring removal tool and press to reassemble.
Tow vehicle inspection
You are probably towing with your daily driver, and it is likely you know its current condition most of the time. But you may not inspect the trailering components on a regular basis. They are usually an afterthought for a lot of people. There are special considerations for towing with smaller cars, covered here.
Take a good light and inspect your hitch mount points under your vehicle. Make sure the welds are intact or the bolts tight. Check the receiver for any cracks, and place the bar into the receiver to check fit. Inspect the hitch retaining pin for rust and cracks. They aren’t expensive. Get a new one if there is any sign of a problem, and think about keeping a spare in your tow vehicle.
Inspect the wiring harness for exposed wires or cuts in insulation. Check the connection to make sure no pins are broken or bent. If using an adapter, make sure its connectors are straight.
Again with the tires. Of course, your tires are important every day and not just when towing. Tires are everything when it comes to vehicles. Everything in driving comes down to tires. If you follow any racing at all, you’ll hear them talk about tire temperatures and wear, and how those can alter performance.
The same applies to your daily driver, except you aren’t trying to maximize speed. But tires are what propel your car, not the engine or transmission. Tires are what stop your car, not the brakes. With faulty or worn tires, or incorrect tire pressures, towing can make a marginal situation and turn it into a failure.
Check tires for even wear, keep pressures at manufacturer’s recommendations, and understand that you may need to change pressure when towing. Check your manual. Jet ski trailers don’t have a very high tongue weight, but you should check anyway.
Driver towing experience
Ultimately, the safest speed at which you can tow will depend on your own experience. When you are new to trailering, it’s easy to forget you even have a lightweight trailer behind you. That isn’t the case with a large boat or camper, but low jet ski trailers behind a tall truck or SUV sometimes move out of view. Depending on the tow vehicle, the weight and resistance might not even register with the driver.
But you have to train yourself to remember it is there. Tight corners will need to be approached with a wider entry to keep the trailer out of the other lane. Changing lanes on the interstate requires more room when moving over. Braking to a stop will take longer distances. How much longer depends on the tow vehicle, the weight of the trailer, and the speed you are traveling.
Jet ski trailers don’t have their own brakes. Boat trailers are often equipped with surge brakes, which engage when the hitch shifts forward as the tow vehicle slows. Larger campers, utility trailers and racing trailers have electric brakes that work in tandem with your tow vehicle and can also be applied manually when you get in a situation where you could lose control of the trailer.
Jet ski trailers are light enough that none of that is needed. Just be aware that stopping will take longer. Brake earlier than usual for stop lights. Accelerate smoothly to prevent jerking the trailer and hitch. Approach and cross bumps and potholes slower and try to avoid them if possible. Remember that you aren’t past any bump until after your trailer axle crosses it, not just when your vehicle’s rear tires get over it.
If you are new to trailering, practice in a parking lot. Try to find businesses that are closed in the early evening or on weekends. It’s getting harder to find them in our 24/7/365 economy, but there are industrial parks that empty out after hours. Try to find one and pay attention to the trailer movement behind you as you move around corner curbs. Play with parking and backing up, too.
While that won’t have an effect on top highway speeds, it will make you more comfortable at the launch ramp, at lunch breaks and at the gas station.
When properly maintained and equipped, modern jet ski trailers are perfectly fine when towed at 65-70 with proper tires. Older trailers may not have tires rated for maximum speeds allowed. In those cases, keep your speed under the tire’s maximum rating. Check your trailer and tow vehicle regularly. Start slowly as you learn, but gradually increase your speeds as you get more comfortable.
While we all want to get to our riding location quickly for maximum fun, we need to do so safely. It doesn’t matter how much fun you could have had if you’re stranded by the side of the road with a flat tire or broken trailer. Carry spare tires and wheels, spare hitch receiver pins, extra trailer coupler pins or locking ones, and even a spare ball and bar if you have one. You never know what you’ll need.
So have fun, but, as always, stay safe!