Entering Simpson Bay Lagoon: Bridges, Fees & What to Expect

Entering Simpson Bay Lagoon for the first time can feel a bit intimidating. Between multiple bridges, different schedules, and a mix of French and Dutch systems (including monitoring different VHF channels), it’s not always clear which route to take or how the process works.

We’ve transited in and out of the lagoon several times on both the French and Dutch sides, as well as between them using the Causeway Bridge. While it might seem complicated at first, it’s actually a straightforward process once you understand how it works.

In this guide, we’ll walk you through the three bridges, how to choose the right one for your boat, when to pay the fees for the Dutch bridges (the French bridge is free!), and what it’s really like going through them so you know how it all works before you get there.

Simpson Bay Lagoon & Its Bridges

Simpson Bay Lagoon is a large inland lagoon split between the French side (St. Martin) and Dutch side (St. Maarten), with the international border running through the middle.

It’s a popular hub for sailors, mega yachts, and cruisers, as it offers excellent protection from the surge and winds common in the Northeast Caribbean.

Staying inside the lagoon also allows for shorter dinghy rides for getting around in Cole Bay in St. Maarten and Marigot in St. Martin.

On the Dutch side, Cole Bay is home to major marine stores, boat services, provisioning, and beach bars, and Marigot on the French side also offers provisioning, marine services, and great restaurants.

You can enter the Simpson Bay Lagoon through the Sandy Ground Bridge on the French side or the Simpson Bay Bridge on the Dutch side. Once inside, you can transit between the two sides via the Simpson Bay Causeway Bridge.

The 3 Bridges at Simpson Bay Lagoon

The three bridges provide access to and movement within Simpson Bay Lagoon, each with its own unique characteristics, schedule, and best use.

Depending on your boat, your route, and the conditions, one bridge may be a better option than the others. Here’s what to expect at each, and when you might choose one over the others.

Sandy Ground Bridge (French Side)

Quick Overview

• Narrower and shallower channel compared to the Dutch side
• Opens twice daily for two-way traffic
• Drawbridge (lifts on one side)
• Free to use
• Bridge operator monitors VHF channel 16  – radio ahead of time to request permission to transit
• Average height when closed: 2.9–3.3 m (9.5–10.8 ft) – varies with tide
• Bridge width: 10 m (30 ft)
• Controlling depth: 3.5–3.8 m (10.6–11.5 ft)

What to Expect

The Sandy Ground Bridge provides access to Simpson Bay Lagoon from Marigot Bay on the French side.

There is a single bridge opening for both inbound and outbound traffic, with outbound vessels going first, followed by inbound boats entering the lagoon once the channel is clear.

Once inside, you’ll follow a marked channel (these weren’t there our first year, and wow was it nerve-racking!) that leads toward the anchorage near the Causeway Bridge on the French side.

When we transited Sandy Ground Bridge in February 2026, we found one section as shallow as 6.5 feet (with a 1.0-foot tide). We draw 5.5 feet, and it got uncomfortably close, though it was brief and manageable at slow speed.

When to Use It

• Best for: French side access, shallower draft boats, and narrower vessels
• Avoid if: you have a wider boat or deeper draft

Simpson Bay Bridge (Dutch Side)

Quick Overview

• Wider and deeper channel compared to the French side
• Opens many times daily, for one-way traffic per opening
• Drawbridge (lifts up on one side)
• Busier, especially with larger yachts
• Bridge fees required
• Bridge operator monitors VHF channel 12 – radio ahead of time to request permission to transit
• Average height when closed: 2.4 m (7.8 ft) – varies with tide
• Bridge width: 17 m (55.7 ft)
• Controlling depth: 6 m (19.6 ft)

What to Expect

The Simpson Bay Bridge is the main entry point into the lagoon on the Dutch side and tends to be the busiest of the three.

As you approach around scheduled opening times, you’ll typically find boats staging and waiting for the bridge to open. Once it opens, traffic moves in one direction only based on the scheduled opening, and things tend to move fairly quickly.

You’ll often see dinghies from nearby marinas assisting and escorting larger boats through the bridge to their assigned slips.

The Dutch bridge operators run both this bridge and the Causeway Bridge, and they like to keep boats moving efficiently to avoid traffic buildup in the area. 

We’ve found this bridge wider and easier to transit, but with the number of boats and the operator encouraging boats to line up tightly before opening, it can feel a bit stressful while waiting.

⚓Side Notes:

• I hear chatter about the new building going up at the entrance from Simpson Bay causing a wind funnel. Something to keep in mind, but we haven’t noticed an effect when we went through.
• Do not go through the Simpson Bay Bridge with your dinghy in the opposite direction of traffic while the bridge is open. 

When to Use It

• Best for: Dutch side access, deeper draft boats, and larger vessels
• Avoid if: you prefer a more relaxed or less crowded entry and have a smaller boat

Simpson Bay Causeway Bridge (Dutch)

Quick Overview

• Dutch-operated bridge
• Located inside the lagoon
• Swing bridge
• Used to move between sides
• Monitors VHF channel 12 – radio ahead of time to request permission to transit
• Average height when closed: 6.2 M (20.3 ft) – varies with tide
• Bridge width: 23 m (75.4 ft)
• Controlling depth: 6 m (19.6 ft)

What to Expect

The Simpson Bay Causeway Bridge (aka Causeway Bridge) is located inside the lagoon and is used to move between the French and Dutch sides.

This swing bridge allows vessels to transit in both directions at the same time, with boats passing on opposite sides depending on direction.

The Causeway bridge typically opens three times a day, with timing coordinated with the other bridge opening times to allow for smooth traffic flow through the lagoon.

We’ve found this bridge to be less busy than the others, and it will not open if there are no vessels waiting to transit through. For that reason, we like to radio ahead (if possible) to let the operator know our plans.

Here’s a view from the Causeway Bridge showing both the French and Dutch sides of Simpson Bay Lagoon:

When to Use It

• Best for: Access to the other side within the lagoon
• Not needed if: you are entering and staying on the same side

Which Bridge Should You Use?

If you’re looking for the simplest and most common option, most cruisers choose the Simpson Bay Bridge on the Dutch side. It’s wider, deeper, and easier to navigate for most boats, especially if you’re arriving from the south.

That said, the best bridge for you depends on your boat, your route, and the conditions, especially when planning your time sailing in St. Martin.

Use the Simpson Bay Bridge (Dutch Side) if:

• You have a deeper draft or wider boat
• You prefer a wider, more forgiving channel
• You’re arriving from the south

Use the Sandy Ground Bridge (French Side) if:

• You are heading to or from Marigot or the French side
• Your boat has a shallower draft
• Weather or anchorage conditions favor the French side

Use the Causeway Bridge if:

• You are already inside the lagoon
• You need to move between the French and Dutch sides

No matter which bridge you choose, it’s always best to consider current weather conditions, your draft, and how comfortable you are navigating tighter or busier channels.

Bridge Schedules & Timing

The bridges for entering and transiting through the Simpson Bay Lagoon are well-timed with each other to allow for good traffic flow. 

The Simpson Bay bridge openings are for one-way traffic only, while the Causeway Bridge and Sandy Ground Bridge allow traffic in both directions during each opening. 

The Simpson Bay and Causes bridges open 7 days a week, while the Sandy Ground Bridge on the French side opens Mondays – Saturdays only. Check the schedule before transiting as these are subject to change for low season and holidays.

It is important to arrive at the bridge prior to the opening. For me, this is the most stressful part of any bridge transit – the waiting around, sometimes in a crowded area until the bridge actually opens. But it is important to be ready and waiting as the bridge operator will not wait for you to get to the bridge.  

Below are the bridge opening times for each bridge. Keep in mind that these are subject to change. There can be fewer bridge openings during low season, and they increase bridge openings of the Simpson Bay Bridge during events such as the Heineken Regatta.

Sandy Ground Bridge:

Simpson Bay Bridge:

Note: You can request a special bridge opening for an additional fee (Occasionally seen for larger yachts)

Simpson Bay Causeway Bridge:

Simpson Bay Lagoon Bridge Fees

Transiting through the Sandy Ground Bridge on the French side is free (🙌), however, there are fees for going through the Simpson Bay Bridge. 

As of March 2026, the Causeway Bridge is free to transit, but this is always subject to change.

You can transit through the bridge first, then pay after you enter the lagoon. There is no fee for using the bridge to exit the lagoon.

You pay for the bridge fee at the Customs and Immigration Office, the same place you clear into St. Martin. Often this is paid for while you are clearing in, as applicable.

Simpson Bay Bridge Fee (Entrance into Lagoon):

Key Details to Know When Passing Through the Bridges

As you approach a bridge opening in Simpson Bay Lagoon, you’ll typically find boats gathering and staging approximately 15 – 30 minutes ahead of the scheduled time. 

Keep your VHF Radio tuned into channel 12 for the Simpson Bay and Causeway bridges and channel 16 for the Sandy Ground bridge to be able to communicate with the bridge operator and other boats transiting the bridge, as necessary.

The last time we entered the lagoon through the Simpson Bay bridge, we heard on the VHF radio that a couple of the larger yachts were requesting to enter the bridge last, as they were going to a dock near the bridge and wanted the boat traffic to clear out before they tried to get into their slip. This helped us know where to fall in line for going through the bridge.

The pace going through the Dutch bridges feels a little more rushed, as there are usually more boats transiting per bridge opening, and the bridge operator likes things to move along in an orderly fashion. Don’t be surprised if you hear him “ask” the captains of transiting vessels to “hurry up”.

Tips for a Smooth Transit

• Arrive early to ensure passage through the bridge
• Have lines and fenders ready in advance, as applicable
• Monitor VHF channel 12 for the Simpson Bay and Causeway bridges and VHF Channel 16 for the Sandy Ground bridge
• Watch for wind and current, especially in tighter channels
• Stay alert and be prepared to move when it’s your turn

FAQs about Simpson Bay Lagoon Bridges

Entering Simpson Bay Lagoon: Key Takeaways

Entering Simpson Bay Lagoon may first seem like a hassle with learning the bridge schedules and the stress of waiting for the bridge openings. However, it is well worth it once you are inside.

The lagoon offers protection from the wind and waves, and shorter dinghy rides to get around St. Maarten and stock up on provisions, visit marine stores for the never ending boat projects, or hang out with fellow cruisers at the wide selection of great restaurants. 

We have passed through all three bridges several times sailing in St. Martin and find them easy to transit once you learn the system. 

Knowing that you don’t have to pay for the Simpson Bay bridge until after you go through and clear into St. Maarten is also a huge help logistically.

If you’re planning your own trip through Simpson Bay Lagoon, we’d love to hear what your experience is like or answer any questions you have.