The Wailua River runs about 20 miles from the slopes of Mount Wai'ale'ale to the sea at Wailua Bay, and its lower stretch is flat, wide, and calm enough that it is the only river in Hawaii you can navigate by boat. That is why every east-side itinerary has a Wailua morning on it. The confusion starts when you try to book one: kayak tours, riverboats, rentals, and paddle boards all sell "the Wailua River" and they are very different days. This page sorts them out.
Read this first: no commercial kayaking on weekends
Guided kayak tours and kayak or paddle-board rentals on the Wailua River run Monday through Friday only. Sundays have been closed to commercial operators since a 2007 state concession agreement that reserves the river for residents; Saturday permits were pulled by the state in November 2021. If your Wailua day falls on a weekend, your options are the Fern Grotto riverboat (which does run weekends), moving the kayak day to a weekday, or bringing your own boat. No shop will rent you one.
The four ways onto the river
1. Guided kayak and hike to Secret Falls
About USD 119-165 per person, 4.5-5 hours, weekdays only.
The signature trip and the one most people mean when they say "kayak the Wailua." Paddle about two miles upstream in a tandem sit-on-top, beach the kayak, walk roughly a mile and a half of valley trail with one stream crossing, and swim under 100-foot Uluwehi Falls (Secret Falls). Guides bring lunch and walking sticks and know which fork of the muddy trail is the right one. Kids from about age 5 do it happily.
Wailua River Kayak & Secret Falls Hike →
Guided Kayak & Hike to Secret Falls (from USD 119) →
For the full breakdown of the trip, what the trail is really like, and every operator side by side, see the Secret Falls kayak guide.
2. Fern Grotto riverboat cruise
About USD 30-40 per person, 80-90 minutes, runs daily including weekends.
The zero-effort option and the oldest tour on Kauai: a covered barge motors two miles up to the Fern Grotto, a lava-rock amphitheater draped in ferns, with live Hawaiian music and hula on the ride. No paddling, no mud, no fitness needed, and it is the only commercial way onto the river on a Saturday or Sunday. Grandparents, small children, and rainy days all point here.
Note: the grotto itself is viewed from a platform; you no longer walk inside it since a 2006 rockfall.
3. Kayak rental, on your own
About USD 47-65 per kayak, weekdays only, back by mid-afternoon.
Same route as the guided trip at about a third of the price for a couple. You get the boat, paddles, a dry bag, and a map; you carry your own food and find the trail fork yourself. Worth it if you have paddled and hiked before and want to linger at the falls. Not worth it as a first-timer: the stream crossing is where unguided groups get turned around by weather, and the trail is genuinely easy to lose after rain.
4. Stand-up paddle board rental
About USD 64, weekdays only.
The same river on a board. Fine for confident paddlers on the flat water; the afternoon return leg is into the trade wind and is real work standing up. Most people who choose SUP over kayak do it for the workout, not the falls.
Launch points and logistics
- Wailua River Marina (Wailua River State Park): the main launch for the riverboats and most kayak operators, on the south bank just off Kuhio Highway. State park entry fee of about USD 5 per person for non-residents applies to some tours; check the listing.
- Kamokila Village side (north bank): some rentals launch from here, closer to the Secret Falls trailhead. Slightly shorter paddle.
- Timing: book the earliest slot you can (7:45-9:00 AM). Morning water is glassy and the falls are empty; 11:30 AM and later meets the wind on the way back.
- Footwear: every kayak operator bans flip-flops and Crocs on the trail. Strap-on water shoes or old sneakers.
- Drive times: 15 minutes from Lihue, 10 from Kapaa, about 45 from Princeville and the north shore, 40 from Poipu.
Which one is right for you
- First visit, want the waterfall, any fitness level: guided kayak and hike (#1).
- Weekend, small kids, mobility limits, or rain: Fern Grotto riverboat (#2).
- Experienced paddlers on a budget: kayak rental (#3).
- Want the workout more than the falls: SUP rental (#4).
More east side
The river is the anchor of the East Side / Coconut Coast. Pair it with Opaeka'a Falls (a roadside overlook five minutes away), Lydgate Beach Park's protected swimming ponds, or the Kapaa bike path. If your trip also includes the north shore, our Haena reservation guide covers the other permit system that catches visitors off guard, and the tour map shows how the river sits relative to everything else.