Nagashima Jumbo Seawater Pool Review: What to Expect at Japan’s Largest Water Park
Last Updated on April 14, 2026 by Kay
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If you’re wondering what it’s like to visit Japan’s largest water park, Nagashima Jumbo Seawater Pool (which is sometimes called Nagashima Water Park), you’ve come to the right place.
Now, don’t let the name fool you. Nagashima Jumbo Seawater Pool is far more than just a single pool (so if you thought it was one massive pool, it ain’t that). This water park is home to multiple slides for all ages and you can easily spend an entire day here, which is exactly what my family did.
Is Nagashima Water Park worth visiting? Hands down yes, especially if you love waterslides and want a park with enough variety to keep you busy for hours. My visit was a mix of genuinely fun rides, a few small annoyances, and some surprises I wish I’d known ahead of time.
Overall, my husband and I were able to do all the waterslides that were open that day (eight) in about three hours, which felt pretty efficient, though I do not think that would be realistic at every time of year. If you go during a busier period, you should expect longer lines and a slower pace. The water also felt colder than at other water parks I’ve visited in Japan, which stood out right away.
Here’s what I’d actually expect before going, plus which rides I thought were most worth your time.
Table of Contents
- Nagashima Water Park: What to Know Before You Go
- Entry to Nagashima Water Park
- Crowds and Wait Times
- Water Temperature
- Phone and Locker Situation
- Water Slide Review for Nagashima Jumbo Seawater Pool
- Best Waterslides for Families or First-Timers
- Pools at Nagashima Water Park
- Final Verdict: Is Nagashima Water Park Worth It?
Nagashima Water Park: What to Know Before You Go
Nagashima Jumbo Seawater Pool is located inside Nagashima Spa Land, which is a massive amusement park in Mie Prefecture. I highly recommend staying at Hotel Nagashima so that you can enter the park 15 minutes early. You can also purchase a ticket for the pool from there on the day you check in, so you can save time the next morning when you go to the pool.
The photo below shows my husband and daughter using the special bridge that connects the hotel to Nagashima Spa Land and its water park, which is super convenient!
Note that Nagashima’s water park is only open during the summer from July 11th to September 28th.
Typically, the pool is open from 9 or 9:30 AM to 5 PM. You can enter the theme park when you’re done at the waterpark, which is pretty great, and there are changing rooms, showers, as well as lockers. Note that you need to buy an all-you-can-ride pass or individual tickets for a ride separately.
Tickets for Nagashima Water Park cost 4800 yen for adults (ages 13 and up), 3300 yen for kids (ages seven to 12), 2000 yen for children ages two to six, and 3500 yen for seniors (65 and up). This ticket allows you to ride all the waterslides as many times as you like, so I think it’s very affordable.
If you like, you can get an all-you-can-ride pass for the amusement park as well for an additional fee, although I feel like it’s best to visit Nagashima Spa Land (the amusement park) on a separate day. It is possible to visit the pool in the morning and the amusement park in the afternoon, but it’s a tight schedule since everything closes at 5 PM. To help with your decision, read about what to expect at Nagashima Spa Land.
Sadly, if you have visible tattoos, you are unable to enter the waterpark. (My tattoo is on my lower back, so my one-piece bathing suit covers it perfectly. I also recommend wearing a rashguard if you want to cover your tattoos.)
You can use credit cards to buy snacks and drinks at the pool, but some stalls only accept cash.
Lastly, many names for waterslides and pools, as well as some signs, are in Japanese only.
Okay, now that’s out of the way, let me share what it was like to visit Nagashima Water Park (Jumbo Seawater Pool) so that you know what to expect when you go.
Entry to Nagashima Water Park
We stayed at Hotel Nagashima, so we were able to get into the park 15 minutes before opening. This was an excellent decision because, although there were many other people (mainly families) heading in with us, there was hardly any wait time!
To get to the waterpark, we needed to first enter the main gate and then head left. It wasn’t rocket science, especially since we could just follow where everyone else in swimwear is going.
After our pass was scanned at the pool’s gate, we were finally at the pool area! Notably, we we had to take off our sandals to step into some water before we could go inside the waterpark. For this reason, make sure you wear sandals you can easily slip off!
If you like, you can leave your things in lockers right next to the entrance. This is also where the showers are located, which you can use before you leave. (They’re located at the very back.)
These lockers require 100 yen coins, though, so make sure you have several on hand (maybe 1000 yen worth) in case you need to use one or two.
Many people were just carrying their things but unlike some other waterparks we’ve been to in Japan, you’re not allowed to place a mat or tent down, so lots of people were leaving their things in the dining space near the restaurants and UFO Water Slide (slider), which are just past the lockers. Below is a picture of what building to look out for:
However, keep in mind that although Japan is generally safe, you’re still leaving valuables out in the open so there is always a risk of something going missing. This is why I suggest carrying a waterproof smartphone case with you and putting your phone, a credit card, and a 1000 yen bill inside.
Crowds and Wait Times
There was absolutely zero wait time for the waterslides first thing in the morning when we visited Nagashima Water Park. For this reason, I was able to do 7 waterslides in about three hours, all that I wanted to ride, which was amazing.
That said, I would not count on that happening if you are visiting during a busier period. I was very aware that during peak summer crowds, this could be a completely different experience. We went on a weekday before summer vacation (mid-July) started, but keep in mind that this may overlap with the rainy season in Japan.
Some lines moved faster than others. For example, the multi-racing slide, which you ride down on a mat, was quick because they let up to 10 people go at once. Other rides, especially those needing a minimum number of riders, could take longer simply because you had to wait for enough people to join.
I’ll explain more about the water slides and my impression, as well as my Japanese husband’s, later on.
Water Temperature
One thing that stood out right away was that the water felt a bit cold compared with other water parks in Japan, and my husband thought the same thing. It was not enough to ruin the experience, but it was noticeable. If you are expecting warm pool water everywhere, this may catch you off guard.
The onsen areas are obviously a different story (yes, there are onsen at this water park!), but for the regular water attractions, we found the water cooler than expected.
Phone and Locker Situation
One of the more annoying practical issues was that you cannot take your phone on any of the waterslides. From a safety point of view, that makes sense, but it does create the problem of figuring out where to put it while you are in line or on the ride.
You can leave your sandals or watershoes next to the lockers as you cannot wear them once you queue for the waterslides. (Don’t leave them in front of the lockers like the person did in the photo above because that blocks others from using the lockers.)
Some waterslides, like the Big One, had a free locker area once you got up the stairs, which helped. There will always be a free locker you can use somewhere, but whether or not it’s close to the waterslide is another issue. This is why I would recommend having a plan for your phone and valuables before you start lining up for a waterslide.
Water Slide Review for Nagashima Jumbo Seawater Pool
There are a whopping eleven different water slides at Nagashima Water Park (Jumbo Seawater Pool). However, two are for children, including one that’s only for children in elementary school and younger.
In this article, I’ll share my thoughts, as well as my husband’s, on the non-kiddy water slides at Nagashima Water Park. As stated earlier, we were able to go on all of them, minus one that was closed.
Note that during busy periods, you can pay for a priority ticket to skip the line for certain waterslides and a pool: Extreme Rapids Pool, Boomerang Twist, Big One Slider, Tornado Slider.
The machines to purchase these tickets are located at the entrance of each water slide. And thankfully these machines take credit cards!
During busy periods, expect wait times without the pass to be about 30 minutes to an hour (or even longer). When we went, we waited about 5 minutes in the morning and then 30 minutes for a waterslide during peak times (about noon to 2 PM).
The water slides also have a minimum height requirement. Many of them require riders to be at least 120 centimeters tall.
Notably, some slides have weight limits, so you may not be able to ride if you surpass that limit. Also, although some rides say “four people can ride” etc., if your group’s weight exceeds a certain amount, you may need to ride separately. You won’t find out until you’re at the top of the slide, where there’s a scale.
Best Waterslides for Thrill Seekers
If you want the more intense rides, a few definitely stood out. Now, in Japan they call waterslides “sliders” but I’ll be referring to them as waterslides in this articles.
Boomerang Twist
The Boomerang Twist felt fast and intense. You ride on a raft, and unless you are already in a group, you will probably be paired with other people so that it has enough weight. I was paired with complete strangers, but it was totally okay!
On this ride, you drop 25 meters and then are propelled up a disc-shaped incline, moving back and forth along it.
At one point, I genuinely thought I might fall off, so I would strongly recommend holding onto the handle very tightly. This was one of the rides that felt the most thrilling to me and I would gladly have gone again if I had time.
This waterslide has a minimum height requirement of 130 centimeters and a minimum weight requirement of 35 kg.
Our rating: 5/5
Mega Abyss
Mega Abyss is the largest funnel water slide in the world, and it ended up surprising me. The first time I rode it, I thought it was a little less fun than some of the other big rides. But when I went on it a second time, I enjoyed it much more.
You need at least four people to ride, so you may have to wait around for enough people to show up if your party doesn’t have the required number. (Or if you were alone like me, as my husband and I took turns going on the waterslides while the other watched our kid.)
You sit in a round raft, there is one big drop, and then the raft (with you in it) is tossed back and forth while spinning through the huge tube (the abyss, I assume) near the beginning of the ride.
Notably, I noticed that the group weight actually changes the experience. I thought it was a little slow and boring the first time, but I was also riding with a group of men. The second time, I was with only women, and we swung around more, which made it much more fun. There is also a rainbow tunnel section that I really liked.
By the end of the day, this may actually have been my favorite ride because it was exciting without feeling too scary. This is an absolute must-ride when you come to the park.
This waterslide has a minimum height requirement of 120 centimeters.
Our rating: 5/5
UFO Waterslide
Shaped like a UFO, this waterslide drops you into a pool that is 2.5 meters deep. You cannot wear goggles, and you must be able to swim. I would only recommend this one if you are a confident swimmer.
My husband said you should use the bar before you launch to push yourself forward with as much force as possible. Otherwise, you can go down awkwardly and not spin around the UFO part the way you are supposed to.
He said it was really fun, though he did get water up his nose when he dropped into the pool, which is why I decided against going on this.
This waterslide has a minimum height requirement of 120 centimeters.
My husband’s rating: 4/5 (if you’re okay with water possibly going up your nose)
Best Waterslides for Families or First-Timers
Not every ride at Nagashima Jumbo Seawater Pool feels extreme, which I appreciated because I needed a break!
Tornado Waterslide
This waterslide has you go down one of several tube slides in an inner tube, and you get to choose!
There were three Tornado Waterslide options open when I visited. Two were black, and one was white. The white one was my favorite because it is open for around the top half, and you spin around more. It felt gentler, wider, and more fun overall. The waterslides are distinguished by letter.
I would describe this one as the right level of fun without being too intense. It was not too fast for me and actually felt a little leisurely in the best way. Out of the bigger slides, this is the one I would recommend for kids (if they’re tall enough) or for anyone who wants something exciting but not overwhelming. I wish my daughter had been tall enough to go on this because I would have loved to ride together!
A practical thing to know is that the Tornado Slider requires you to carry an inner tube up a lot of stairs, and they are heavy. There is both a single inner tube and a double. They are not impossible to carry, but after a while, it definitely starts to feel annoying, especially if you’re alone like I was.
This is not a dealbreaker, but it is one of those little things that can make the day more tiring than you expect.
This waterslide has a minimum height requirement of 120 centimeters.
Our rating: 4.5/5 (0.5 docked for having to carry up the inner tube)
Surf Hill Waterslide
One of the most fun waterslides was the Surf Hill, where you lie tummy-down on a mat and race other people. It is simple, but it works. The line moved quickly because they allowed up to 10 riders at a time, so don’t worry if it looks long, and it was just genuinely fun to race.
This waterslide has a minimum height requirement of 130 centimeters, a maximum weight limit of 80 kg, and a maximum age limit of 55 years old.
Make sure to grab a mat before you line up! There are two sizes, one for adults (the blue sign reading 大人用) and one for kids (the green sign reading お子様用).
Our rating: 5/5
Water Slides I Would Skip or Prioritize Less
The Big One
The Big One was not bad, but I liked it less than the other major rides. You go down a 250-meter-long path on a raft that moves back and forth. It feels more leisurely overall, though you do get very soaked on it.
There is a locker when you go up the stairs, which is useful, so at least that part is convenient. But if I had limited time and had to choose between this and some of the other rides, I would probably prioritize something else first.
This waterslide has a minimum height requirement of 120 centimeters.
Our rating: 3/5
Wild River
Located right next to Surf Hill, Wild River reminded me a bit of the Tornado Waterslide as you also go down on an inner tube, except it was more gentle and open.
You spin around a lot, which I enjoyed, and because it is wider, it felt less intense. The line moved a little slower, though, since only one person could go at a time using the yellow inner tube.
I definitely think the Tornado Waterslide was more fun.
This waterslide has a minimum height requirement of 130 centimeters and a maximum weight of 80 kg.
Our rating: 3/5
Free Fall Waterslide
The Free Fall Waterslide drops you from a height of 23 meters at a 60-degree angle. I don’t like near-straight drops so I asked my husband to do this one while my daughter and I excitedly watched.
Before his turn, we saw lots of other people go down, and many of them got water up their noses and said it was unpleasant.
My husband’s nose was spared, but his back hurt because it bumped against the slide repeatedly while going down. He said that although it was fun, he wouldn’t do it again.
This waterslide has a minimum height requirement of 140 centimeters.
My husband’s rating: 3/5
Water Tube
This waterslide was closed when we visited Nagashima Water Park. As the name suggests, it’s a tube waterslide that has you drop into a pool that’s 1.8 meters deep.
Only those junior high school age (13 years old) and up can go on this waterslide.
Pools at Nagashima Water Park
Okay, now with the waterslides out of the way, let’s get into the pools.
There are seven pools at Nagashima Water Park. Three of those pools are more for families with young children, so I’ll cover the larger ones below.
Extreme Rapids Pool (超激流プール)
The Extreme Rapids Pool was one of the most fun ones I’ve ever been on. It’s like a lazy river where you travel along a path on an inner tube, but the speed makes it the complete opposite of a lazy river. You’re allowed to go around three times, although this works on an honor system, as no one is really checking.
(Sorry for the lame photo below, it was impossible to get a photo without a bunch of people in it.)
Make sure you pick up one of their inner tubes at the entrance of the “pool”. You do not need to bring your own. Green inner tubes are for adults and yellow are for children.
What I found makes this pool especially exciting than most is the giant wave that comes around about once every lap and pushes you forward. It gives the ride a little extra energy and keeps it from feeling too slow or repetitive.
The only annoying thing is that you have to keep holding onto the grip on your inner tube. The lifeguards will call you out if you are not holding on, so this is not the kind of lazy river where you can totally relax.
Still, it was one of my favorite attractions in the park.
This pool has a minimum height requirement of 130 centimeters. However, children who are between 120 cm and 130 cm tall can go in this pool if they wear a life jacket.
Our rating: 5/5
Lazy River
This is a standard pool that’s at every waterpark in Japan, and there is nothing particularly special about this one. These do get very crowded, so keep that in mind if you want to go in.
My daughter enjoyed it for a lap, but she preferred the kids’ area more.
Our rating: 3/5
Surfing Pool
This is the biggest pool at Nagashima Jumbo Seawater Pool and what the water park is most known for, as it’s named after this pool. Unsurprisingly, it contains saltwater.
About every 30 minutes, they play popular JPop hits for about 4 minutes while the pool turns into a wave pool and water sprays into the pool. It’s really enjoyable but it can get very crowded.
Onsen Pool
There are two onsen pools at Nagashima Jumbo Seawater Pool, a small one located next to the large Surfing Pool and another in the kiddy area.
Here’s what one of the onsen pools look like:
These onsen pools are a nice bonus, especially if you want a break from the slides.
That said, they were very hot.
If you want a slightly less hot onsen pool, go to the one in the kids’ section. You may notice small yellow or orange flakes in the water, but that is completely normal because it is real hot spring water.
There are also showers with onsen water, which you can use to rinse off. However, you do not use any body soaps etc., here!
Final Verdict: Is Nagashima Water Park Worth It?
Yes, I do think Nagashima Water Park is worth visiting, especially if you want a water park with a good range of attractions and some memorable slides. We ended up spending the entire day here, so we visited the theme park the next day.
What I liked about Nagashima Water Park is that it did not feel like a one-note park. There were thrill rides, more relaxed attractions, kid-friendly options, and onsen pools all in one place. That made it feel more complete than a park that only focuses on extreme slides.
My personal highlights were the Boomerang, the Tornado Waterslide, the Surf Hill Waterslide, and eventually Mega Abyss.
The biggest downsides were the cold water, the inner tubes, the hassle of dealing with storing your phone, and the fact that the waterslides closed by 3:55 PM. But even with those issues, I had a really fun time and would still recommend Nagashima Water Park (Jumbo Seawater Pool).
If I went again, I would do the same thing I did when I first visited — stay at Hotel Nagashima, head straight to the major waterslides early, save the onsen and more relaxed areas for later, and make sure I rode my favorites again before the slide closures kicked in.