Waihee Ridge trail is a nice hike with gorgeous views - 2 miles there and back. 13 crossings is another nice one that ends at a waterfall you can swim under (only 1 mile there/back but not as well marked and parking is tricky). Closer to you is the Kings Trail - across black lava out to some gorgeous ocean cliffs and empty space. Snorkeling can be done at the beach in front of the Kea Lani, but being summer the trades pick up mid day so for snorkeling or surfing they’ll need to wake up early and get on it.

Flyin Hawaiian zipline!

Ironwood Ranch in Napili is great for horseback riding. If you opt to ride make sure you pack closed toed shoes and long pants.

Horseback riding is another fun activity - there are quite a few stables and no riding experience needed.

Highly recommend the Kaanapali Surf Club for surf lessons. The waves on Kaanapali Beach were perfect for it. Schedule a morning lesson. We did a semi-private for our two kids to share in instructor. Highly recommend that over the group lesson.
https://kaanapalisurfclub.com/lessons/

Road to Hana - there are a lot of stops as part of the drive where you can stop to swim, hike, see scenery.

We really loved the Maui Costco - so many interesting snacks and the mango smoothies at the food court were so good. Also Poki bowls - there are 2 locations (one more south and one more north - I can't remember the names but the one more south is a food truck) where the fish is from fish caught that morning so that the fish they use may differ depending on the catch.

Maui Wave Riders for surfing

Maui Sailing Canoe as option for snorkel trips (leaves from near Fairmont in Wailea)

Need to get sunrise tickets 2 months out from nps website

I just booked our trip yesterday! QWe bought first class tickets out of Dulles - they were not hugely disparate with economy class tix. Only 1 stop and direct into Maui. Going with similar age kids. I booked 2 rooms (all the rooms are suites) at the Fairmont Key Lani as the Four Seasons was sold out of all their double queen bed rooms and all the other options there were too expensive. The concierge at the hotel can help you out with all the activities for your kids. There are lots of fun hikes too. Definitely do the bike trip down from Haleakalā. The other hotel we looked at was the Grand Wailea Resort. They too can help you book surfing, snorkeling, etc for the kids.

Considering same. What flights are you looking at?

Doing this totally last minute - any advice for Maui for family of 4 with 2 teen sons, 1 week in August. They want to take surfing lessons, learn to snorkel, go boogie boarding, go hiking if possible. We plan to see Haleakala one day. Any recommendations for the above appreciated. Any other must do activities ? Hotel suggestions? TIA !