What are the best companies to use for day trips on virgin Gorda? Likely do a full day trip to snorkel and traverse the island for 4 adults and 1 child. We will be arriving next Saturday.

Sorry but I can't quite tell from your post if you are coming over to VG for the day and looking for something like a tour to "traverse the island" or are you staying on VG and looking for a day trip FROM VG to snorkel different spots?

If you are just coming for the day from Tortola, I honestly recommend renting your own car and driving yourself around. It's ~$65/day for the Suzuki Grand Vitara (significantly cheaper than any taxi) and then you can go anywhere you want, on your own schedule.

Speedy's will meet you right at the ferry dock with your rental car. Just remember to drive on the left!!

Hit The Baths first thing, then hit Hog Heaven for lunch. Then if you're keen on checking out the North Sound catch a ferry from Gun Creek over to Saba Rock or Bitter End Yacht Club. Rent e-foils or take a kite lesson from Saba, or go rent a Hobie Cat from BEYC and cruise around the North Sound!

If not interested in the North Sound, head to one of Virgin Gorda's many beaches, check out the Copper Mine Point, or go relax for the afternoon at CocoMaya

If you do prefer a guided tour/are not comfortable driving around, Sweet Ice Willie is my recommended guy.

Sweet Ice - +1-284-544-8073. Great attitude, nice vehicles, safe driver.

Sorry, we are staying on virgin Gorda for the week. Looking for a day boat trip.

Tons of options then, just depends how much you want to spend.

The cheapest option is Bradley Power Boats out of Leverick Bay. They allow bareboat rentals or you can hire a Captain as well.

Most affordable way out on the water for the day is to do an organized trip. These are called join-ins and average about $160/pp. Check out Bradley Powerboats as well as DiveBVI for itineraries and options. You can view different trips on both websites. These are a great way to see multiple popular spots (Willy T, Indians, Soggy Dollar, etc). Both are great companies.
Fully private day charters allow you to customize your day but are going to start at over 1k regardless of how many people you are. Plenty of good options for who to use.
Let us know which way you lean so we can help you either pick which join in fits your wants or which companies you may want to inquire about private hire.

This is good advice. Forgot about the join-in trips!! Definitely the most affordable option