My husband and I stayed at Papakea a long time ago and there is pretty much no beach there, we drove

Blackrock beach was our favorite for snorkeling in that area. We saw turtles and a ton of fish and the water was usually calm with easy entry. The Sheraton Blackrock fronts that beach. I've recommended it to many of my friends who honeymooned on Maui and they loved it. There are also other places to stay on that beach too and Whaler's Village is right there, with restaurants and shops (we enjoyed Hula Grill). If you would like a condo, the Aston at the Whaler is right there.
This is the opposite end of the island, but the Makena Beach and Golf Resort has excellent snorkeling. You can usually find turtles there too. This is a much quieter location than Kaanapali. In general the ocean is calmer along southern shores in winter and north in summer.
My recollection is the other side of Black Rock, going away from the major resorts, was much, much less crowded. I stayed at the Royal Lahaina Resort -- not the height of luxury by any means when I was there. But it was in a great, uncrowded location on the quieter side of Kaanapali, a short walk to Black Rock and the other resorts and restaurants. I believe kansas city hotels on the plaza it's been renovated since I was there, so it's probably much nicer now.
I walked by when I was there in September. The units near the beach are in a lovely setting, but there's also a high-rise that looks dreadful. I think the whole place might be in the midst of renovations, but I'd be careful when planning.
I personally like the busier (south of Black Rock) part of Kaanapali Beach, but there are some nice properties north of Black Rock (Westin Villas, Honua Kai). I wouldn't go farther than Honua Kai (I don't like it because there's a fence so once you're at the end of the Honua Kai property, you can't walk any farther on the beach path) and go straight to Napili if quieter West Maui is your choice.
My husband and I stayed at Papakea a long time ago and there is pretty much no beach there, we drove every day a short distance up to Kapalua to swim and snorkel there, nice beach. The condos in the Napili area looked pretty nice at the time.
Outrigger Napili Shores is a good choice, they are right next to Napili Bay which has some awesome snorkeling AND you can't go wrong with the mac nut pancakes from the restaurant on property. They have an oceanfront pool too.