The most popular choice for seeing Kauaʻi from the air is to take a helicopter ride. You’ll have to decide what kind of aircraft you want to fly in, what kind of tour you want (some land in neat places), and whether you want the doors on or off (some passengers like the visibility, others don’t like the exposure to wind and possibly rain). Most helicopter tour companies depart from the airports in Lihuʻe.
Trips generally last 60 to 90 minutes, and start at around $289 (make internet reservations ahead of time to save some money). Doors off helicopters are totally the way to go if you are an avid photographer (and suffer little from vertigo). But it's noisy and windy, and maybe just a little bit scary. On a six-seater helicopter, two people may be stuck in the middle. You can request a window, but the captain may move people around for weight balance.
You also get to choose from big window, little window and bubbles (like the ones on MASH). The big difference is always visibility and noise. More modern helicopters are quieter and generally have big windows. You always wear earphones so you can talk with fellow passengers and lower the noise, but even the slight reduction in sound can make your trip more pleasant. Then again, some of the older helicopters have that sweet Magnum P.I. feel that make for a thrilling ride.
Rain delays do happen, and tours will vary their route based on rain and winds. Make sure to check the weather policy with your operator before booking. Generally 24-hour cancellations are required. Consider booking early during your stay, so you can reschedule later if need be.
What should you bring? Ideally, strap everything down (hats, cameras, iThings etc). It can get a little cold, so bring a jacket and long pants, plus decent shoes in case your tour does a landing.
You always approach a helicopter from the front (never the back). The captain will generally indicate what side you should board on. Put your head down and hold onto your hat (just like they do in the movies).
From Lihuʻe, expect to see the Nawiliwili Harbor and the Menehune Fishpond, Kipu Kai and the Tunnel of Trees, Manawaiopuna Falls in Hanapepe Valley, Olokele Canyon, Waimea Canyon, the Na Pali Coast, North Shore beaches like Keʻe and Hanalei, and Mt Waialeale. While the rips up impossibly steep canyons are an adrenaline junkie's dream, it's really the close proximity to waterfalls – many of which can only be seen from the air – that make these trips amazing.
While the tours follow pretty standardized routes, you can talk with your pilot to customize the tour experience, especially if it's just you and your family or sweetheart taking the flight. This means getting closer – or further away from the ground – making more acrobatic banking turns or going with a more easy-breezy approach, and generally determining the way you fly.
Tours include ongoing narration from the knowledgeable pilots. Yes, you can tip them afterward, but it's not required.
For a really unique trip consider doing a tour to Niʻihau. The trips can be combined with diving and hunting adventures. Niʻihau Helicopters does a flyover of the island and ends with snorkeling, while Niʻihau Safaris includes air transport and the hunting of boar, feral sheep and oryx.