Heading out from the Koko Marina Center in Hawaii Kai, the 50-foot catamaran takes about ten minutes to reach the dive site within view of Koko Crater. The submarine scooters used on this tour are a second-generation design originally imported from St. Thomas, first invented back in the 1990s. What makes this setup different from standard snorkeling or scuba is the helmet — you duck under the water, pop up inside an air-filled bubble, and breathe normally while your shoulders stay wet and your head stays completely dry.
2024 Hawaii Runner-up: Best Family Attraction in Hawaii — 10Best/USA Today
This family-friendly adventure from Island Water Sports Hawaii takes visitors under the surface of Oahu’s Maunalua Bay aboard self-propelled, eco-friendly scooters. You don’t need any diving experience, and the tour operator even advertises that non-swimmers can take part. The whole experience runs about two hours, with roughly 20 minutes actually on the scooter, plus free time afterward to snorkel.
This is a genuinely unique way to see reef life without scuba certification, but the 20-minute scooter window is tight — especially if the tour is near its 30-person capacity. Smaller groups get more time underwater, so booking a less popular slot matters more than you’d think.
Orienting yourself around Maunalua Bay and Koko Crater
The tour operates out of a single location on Oahu’s southeastern shore, which keeps logistics simple.
Check-in happens at the Bob’s Hawaii Adventure office inside the Koko Marina Shopping Center, behind Jamba Juice and next to Kona Brewing Company. Parking is free anywhere in the shopping center. If you’re driving from Waikiki, you take the H-1 East Freeway until it becomes HI-72 (Kalanianaole Highway), then keep east until you reach the marina. The dive site itself sits within view of Koko Crater, a volcanic tuff cone that’s visible from the water and gives the location its name — the Koko Crater dive site.
The catamaran holds up to 30 people, with seven scooters available per tour. That means riders rotate in groups, and the actual time each person gets on the scooter depends on how many show up. On a quieter day with 18 participants, one rider reported getting about 35 minutes instead of the standard 20. The tradeoff is straightforward: book a full tour and you’ll spend more time waiting on the boat than underwater.
Non-swimmers wanting underwater access
Families with kids aged 10+
First-time visitors with no scuba interest
What the underwater scooter ride actually feels like
Getting onto the scooter takes a moment of adjustment, but the mechanics are simpler than they sound.
You grab the rim of the helmet, bob under the water briefly, then reemerge inside the helmet, take a seat, and grab the handlebars. The helmet works on the Bell Theory — oxygen stays trapped inside while your shoulders and below stay wet. Your head stays completely dry, and you can see through the clear dome with nearly 360-degree visibility. No mask, no regulator, no equalization beyond a few yawns to adjust to the pressure change, similar to what you’d do on an airplane.
You control the engine with a lever by your right hand. It’s not fast — the scooters move at a gentle cruising speed — but the point isn’t speed. A guide manages the mechanism that controls depth, so you don’t have to think about buoyancy. If you want to surface sooner, you just point upward and the guide brings you up.
Marine life and the bait bag trick
Each scooter comes with a small metal mesh bag filled with bait. When you scrunch the bag in your hand, small particles escape and trigger a feeding frenzy. During my tour, ōpelu (mackerel), endemic lauwiliwili (milletseed butterflyfish), and darker-than-usual pualu (yellow surgeonfish) all appeared within seconds. The guides also pointed out green sea turtles when they were around — the tour is marketed partly as turtle watching, though sightings depend on the day.
During whale season, which roughly runs from December through April, the guides mentioned that whales sometimes come right up to the sandbars in the bay. That’s not something you can count on during a 20-minute window, but it adds a layer of possibility that standard reef snorkeling doesn’t offer.
The scooters are equipped with a small bait bag that you squeeze to release particles — this is what brings the fish close enough to see clearly. Without it, the reef visibility is good but the fish stay at a distance.
Practical planning for the submarine scooter tour
Two time slots are available each day, and the differences between them matter more than most people expect.
The tour runs at 9:00–11:00 AM and 12:00–2:00 PM, with check-in 30 minutes before departure. The earlier slot tends to have calmer water and better visibility, especially in summer when afternoon trade winds pick up. The later slot gives you more sunlight for the post-scooter snorkeling portion, but the bay can get choppier.
Pricing is straightforward: riders aged 10 and over pay USD 191.48. Observers aged 4 and over pay USD 138.08, and children aged 0–3 pay USD 78.39. Observers stay on the boat and can use the provided snorkel gear during the free time portion. The tour includes bottled water, snacks, a wetsuit jacket, and snorkeling equipment — mask, fins, and snorkel.
| Detail | Morning slot (9–11 AM) | Afternoon slot (12–2 PM) |
|---|---|---|
| Check-in | 8:30 AM | 11:30 AM |
| Water conditions | Calmer, better visibility | Chopper, wind possible |
| Light for snorkeling | Good but lower angle | Brighter, longer sun |
| Whale season advantage | Earlier = calmer spotting | Warmer surface temp |
Physical requirements and restrictions
Participants must be between 4 feet and 6 feet 8 inches tall, with a weight limit of 350 pounds. The age minimum is 10 years old. Guests with asthma, other respiratory problems, or heart and cardiovascular issues are not permitted to participate. That’s a firm restriction — the helmet-based breathing system creates a sealed environment that doesn’t accommodate respiratory conditions well.
If you have asthma or any respiratory condition, you will be turned away at check-in. The operator enforces this restriction strictly — no exceptions, no refunds if you show up and can’t participate.
Getting there from Waikiki
The drive from Waikiki to Koko Marina Shopping Center takes about 25 minutes without traffic. You take the H-1 East Freeway until it ends and becomes HI-72 (Kalanianaole Highway), then continue east past Hanauma Bay until you see the shopping center on the left. Turn in before the Texaco gas station. Parking is free, and the office is located behind Jamba Juice, adjacent to Kona Brewing Company. If you’re relying on rideshare, factor in that the return trip from Hawaii Kai to Waikiki can be slower in late morning when traffic builds.
On the ground — what to bring and what to expect
The tour provides the essentials, but a few items make the difference between a comfortable morning and a soggy one.
Packing for the boat ride
The catamaran has shaded seating, but you’ll be in the sun during the snorkeling portion. A reef-safe mineral sunscreen is worth bringing — the bay is part of the Maunalua Bay ecosystem, and standard chemical sunscreens are discouraged near reef areas. The tour provides a wetsuit jacket, which helps with buoyancy and sun protection, but your legs will be exposed. A quick-dry travel towel is useful for the ride back, since the changing space on the catamaran is basic.
Michael and the kids came along on a morning tour last spring, and the one thing I wished we’d packed was a waterproof phone pouch. The guide takes photos and videos during the scooter ride that are available for purchase afterward, but having your own dry bag for the boat means you can grab shots of the crater and the marina without worrying about salt spray.
What to do after the scooter ride
Once your scooter rotation is done, the boat stays anchored for about an hour of free time. The tour provides lifejackets, fins, and snorkel gear, so you can jump in and explore the reef on your own. The water depth at the site is manageable for surface snorkeling, and the fish tend to stick around if the bait bags have been active. If you’re traveling with kids who are 10 or older and want to try the scooter, the observer option lets younger children stay on the boat with a parent while the other adult rides.
For those interested in other Oahu water activities, the range of water sports available across the island is worth exploring on a longer trip. The Koko Marina area itself has restaurants and shops, including Kona Brewing Company right next to the check-in office, which makes for an easy lunch stop after the tour.
- Book the morning slot for calmer water and better visibility — afternoon winds can reduce clarity.
- Smaller groups get more scooter time; ask about group size when booking or choose a weekday slot.
- Bring a reef-safe sunscreen and a dry bag — the wetsuit jacket covers your torso but not your legs.
Underwater scooter rides in Hawaii — your questions answered
Do I need to know how to swim for the submarine scooter?
No. The tour operator advertises that non-swimmers can take part. The helmet keeps your head dry and breathing normally, and the guide controls depth. You sit on the scooter the whole time. That said, the free-time snorkeling portion afterward does require basic comfort in the water, and lifejackets are available.
How long are you actually underwater on the scooter?
The standard time is about 20 minutes, but it varies based on group size. With 18 people on a tour that has seven scooters, one rider got 35 minutes. With a full group of 30, you’ll likely get closer to the advertised 20 minutes. The tradeoff is real — smaller groups mean more time underwater.
What happens if I have asthma or a heart condition?
You will not be permitted to participate. The operator lists asthma, respiratory problems, and cardiovascular issues as firm restrictions. There are no exceptions, and you won’t receive a refund if you show up and are turned away. If this applies to you, the observer ticket lets you enjoy the boat ride and snorkeling instead.
Is this better than snorkeling at Hanauma Bay?
They’re different experiences. Hanauma Bay has denser coral and more diverse marine life, but requires swimming and mask skills. The scooter tour gives you access to the reef without any of that, plus the bait bag brings fish closer than you’d typically see while snorkeling. If you want to see turtles and reef fish without getting your face wet, the scooter wins.
What’s the minimum age for the scooter?
Children must be at least 10 years old to ride the scooter. Kids aged 4 and over can join as observers on the boat at a reduced rate. Children aged 0–3 pay the lowest observer rate. The age limit is based on the physical requirements of the helmet and scooter setup, not on swimming ability.
One last thing about that 20-minute window
The submarine scooter tour gives you a way to see reef life that doesn’t require certification, swimming skill, or even a mask. But the real value isn’t in the scooter itself — it’s in the bait bag. That small mesh pouch changes the dynamic of the reef, pulling fish in close enough that you notice details you’d miss while snorkeling: the way ōpelu shift direction as a group, the specific pattern on a lauwiliwili’s fin, the darker tone of a pualu that’s been feeding in deeper water. For a different kind of Oahu experience, consider pairing this with a morning hike up Diamond Head — both are short, structured activities that leave the rest of the day open.
Sources and further reading
Submarine Scooters at Island Water Sports Hawaii — 2024 Hawaii Runner-up Best Family Attraction. 10Best/USA Today, 2024.
Taking a Submarine Scooter Tour Showed Me Oahu’s Underwater World in a Totally New Way. Viator Travel Blog, 2024.
BOB’s Hawaii Underwater Scooter Adventure & Turtle Watching Tour. Hawaii Activities, 2025.
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