We have wanted to explore St Barts (St. Barthelemy) for years but as I am a "seasick sailor", we never got around to taking the ferry. This may be the year we do this! We plan on flying to St. Barts for the day and renting a car. Here are my questions:
1) Can you fly from the French side of St. Martin to St. Barts and if so, what airline services the route? (My research only turned up Dutch-side departures). I'm just looking for options.
2) Any rental car suggestions?
3) For those that have taken the trip, what are your favorite things to do?

Any and all advice is greatly appreciated! We'll be visiting SXM Nov 21-Dec 5th, 2023 and will go for a day trip to St. Bart's sometime around Nov 30th.

Haven't flown them myself but St Barth Commuter flies from L'Esperance airport in Grand Case to St. Barts. No idea on the rental car. As far as things to do, drive around to some different beaches, do some shopping in Gustavia, and have a nice lunch somewhere. Bring LOTS (!!) of money. Enjoy!

Hi. We enjoy going over. I will only fly and if we go we take the St Barth Commuter from Grand Case. It’s been a while but I think it was 189 round trip. 10 minute flight. Easy to explore - rent a car at the airport and have a taxi take you around. If you shop - some of the high end shops have great deals. Hermes, Longchamp, Bulgari etc. Havent been since after Irma but before Covid. So not sure what’s still there. We’ve walked from town to Shell Beach and have visited many others. I enjoy it. It’s pricey! But depends on your idea of pricey!!

As others have said SBH Commuter is the way to go from Grand Case (SFG).
https://www.stbarthcommuter.com/en/

TopLoc is a good rental car company and quite reasonable for a day trip price.
https://www.toplocstbarth.com/EN/

Would bring some swimming stuff and check out Gouverneur Beach, usually pretty clam and nice clear water.
https://www.access.sb/en/st-barts/leisure/beaches/plage-de-gouverneur/

Can spend quite a bit of money for lunch at one of the nice hotels but some other options in Gustavia as well.
Reasonable lunch Pre-Fixe menu here, plus a great view.
https://www.en.ateliersaintbarth.fr/rooftop/rooftop-lunch/1

This has been very helpful. Thank you Carol, Kim and erb923!
Teresa

Teresasxm - We flew over to St. Barts for a day trip a few years ago and it was very worthwhile. At the time you could not fly from PJIA to St. Barts unless it was a connecting flight and we had been on island for a few days already. So we took a taxi to Grand Case airport and flew on St. Barts Commuters from there. I wish I could find the pictures from the flight as I was seated right behind the pilot and it is an exciting landing!! We rented a car from Avis right across the street from the airport and the representative from Avis was very helpful and suggested a plan for the day. He suggested we go to an observation point which is the highest elevation on the island and has quite a view. Then we went to Anse de Grande Saline for a swim in the ocean. We then headed to Gustavia parked the car and walked around looking at the huge yachts and window shopped at the high end stores. I did buy a tank top from a shop there (that was within my budget :D). Then we had lunch at Le Select which I believe was the inspiration for Jimmy Buffet to write "Cheeseburger in Paradise" and yes I had a cheeseburger. Then we returned the rental car and sat at a little cafe across the road from the airport and watched the world go by until our flight back to SXM. It was a great day.

I assume you had to go through French customs ? With your passport? I have been in St. Barts by ferry from Sint Maarten, but I don't remember what we had to do for entry.

We needed our passport when we took the Edge.

Fly or ferry, bring your passport. The best move is to fly St Barth Commuter out of Grand Case.

I recommend two car rental agencies, Gumbs or TopLoc.
https://gumbs-car-rental.com/
https://www.toplocstbarth.com/EN/

Both are located in the airport, 50 yards to the right of the exit from Immigration. Both are locally owned, and both have excellent reputations.

A tour around St Barth is easy enough to do on your own, with a basic map from the rental agency.

It’s possible to do lunch on SBH for no more than lunch on SXM, but you have to work at it. Personally, I recommend doing a blowout lunch. Make a lunch reservation at Eden Rock (or one of the other high-end beachfront hotels).

Parking in town can be a challenge, There’s a municipal pay lot near the ferry terminal, and usually-full street parking around town. (Ask about the Blue Disc, which gets you limited time free parking if you can find a space.).

Many of the high-end boutiques are near the pay lot. There are smaller and less expensive shops as you walk through town.

We definitely would have had our passports with us. As far as going through French customs if I recall it wasn't much at all. Welcome to St Bart's.

a few ideas, not in any particular order:

just take a drive around the island...but fyi, if you're one of those that thinks driving on SXM is stressful, you're in for a surprise on SBH...some very narrow cork screwing roads that wind up/down some pretty steep hills...rent a SMALL car, and beware speed bumps

check out the overlook in Colombier...excellent high up panoramic ocean views, even has a map showing you what you're looking at...down below you can see the cove of Colombier, one of our favorite beaches, but it's an offroad hike so save the beach for another visit

go to Nikki Beach, famous bar/restaurant in St. Jean (east side of Eden Rock)...you might even see some celebs and billionaires partying and dancing on the tables, especially if you go on a Sunday afternoon

go up to the lighthouse above Gustavia...awesome views of the town and marina...especially if the harbor is full of mega yachts

in Gustavia, have a burger and a beer and/or Ti' Punch at Le Select...although according to JB himself, not his actual inspiration for "Cheeseburger in Paradise", but he did spend a lot of time there and was very good friends with the original owner, Marius, who passed away in 2020 at 97 y/o..."dive bar" with a lot of character and cool pics on the walls, (although dive bar in SBH is an oxymoron)

right in Gustavia is Shell Beach...might be my favorite beach...beautiful small beach in a very picturesque cove...great for people watching and you can have a drink at the bar/restaurant Shellona right there

from the roundabout above the airport, watch planes pass just over your head as they land