My husband and I are headed to the Palms the end of April. We'd like a snorkeling trip but would prefer a small group. Does anyone know of a tour group that offers smaller trips? Also do you get bitten just being outside in general? Do I need to apply deet instead of sunblock or a combination?
Any help would be appreciated.

www.JBTours.com takes out small groups. They need 8 minimum, and I've never known them to have more than 15 people at a time.
You can also snorkel in front of Coral Gardens, (20 minute walk down the beach) or find Smith's Reef in the Turtle Cove area, excellent off beach snorkeling.
At dusk, sometimes the no-see-ums come out, and the restaurants are outdoors, so I would spray. During the day and on the beach you're fine, no bugs.

We were there a month ago, and only got bitten in the evening while walking.

JB Tours is the way to go, and if you get Captain Kevin tell him that some woman on Fodors told you he told her he was 40!!! LOL

Just returned from Provo - no bugs "no-see-ums" during the day - but definitely out at night. They seemed to like me better than my husband .

We also did an "Island Getaway" with J&B tours. The just dropped us on our own private island beach with chairs an umbrella and a cooler for the day - we snorkled right off the beach ourselves.

We did see their snorkel tours, and they didn't seem packed with people, maybe 8 people max. The only snorkeling boats that seemed really full was anything coming from the Beaches resort.

The Palms has an excursion company that works out of the resort. Called Caicos Dream Tours. I find them to be one of the better excursion companies on the Island. They do half and full day tours with 8-10 people max.
Have a great trip