Water Adventures Around Sønderborg

Sønderborg is a city blessed with water all around – from the calm Alssund to the waves of the Baltic. Since moving here, I’ve grown to love the sea, and rarely does a day go by without enjoying it in some shape or form. In fact, Sønderborg is surrounded by so much water that it’s arguably one of Denmark’s best areas for watersports – you can almost always find a sheltered spot or a breeze when you need it.

I admit, I’m such a water lover that I even joined Vikingeklubben (our winter bathing Viking club) to enjoy a dip year-round – in winter the sauna is switched on! But whether or not you’re as crazy as me, there are plenty of warm-weather water adventures to try here.

Do you want to know the water temperature? There’s a good website that has a thermometer in the water by the viking club.

In this post, I’ll share my favorite water activities around Sønderborg – from beaches and bathing jetties to paddleboarding, kayaking, sailing trips and more. Let’s dive in!

Blue Flag Beaches

One thing I love bragging about is that we have nine Blue Flag beaches in the Sønderborg area. A Blue Flag is an international certification that tells you the beach has excellent water quality, proper facilities like toilets and waste bins, and meets high standards for safety and environmental care. In short, when you see that little blue flag flying, you know the beach is clean, safe, and well looked after – ideal for a swim or a family day out.

The nine local beaches include (map at the end of the post):

• Drejby Strand (at the southern tip of Als on Kegnæs)
• Vemmingbund Strand (a shallow, very kid-friendly beach in the bay)
• Alnor Strandpark (near Gråsten, by the fjord and the royal palace)
• Lågmaj Strand (a cozy beach by Egernsund, on the Flensburg Fjord)
• Fluepapiret (Sønderborg’s own city beach just east of the Castle)
• Den Sorte Strand (more on this local favorite soon)
• Fynshav South Beach (great for families near the ferry harbor)
• Købingsmark Beach (on North Als, by a big summerhouse area)
• Mommark Strand (a lovely beach next to Mommark Marina)

Each beach has its own vibe – from the breezy Drejby to the tranquil Vemmingbund. On a hot summer day, you’ll find locals spread across all these spots, sunbathing, swimming and enjoying beach picnics.

There is a total of 24 beaches where the water quality is checked and a few more that are too small to be noted.

Favorite Swimming Spots & Jetties

Beyond traditional beaches, we’ve also got some great bathing jetties – ideal for those who like to jump right into deeper water. Our personal go-to is Den Sorte Strand right in Sønderborg. It’s a small sandy stretch but has a fantastic long bathing jetty, complete with a platform at the end and a ramp so anyone can get in the water easily. We love heading there for an evening swim – it’s walking distance from downtown and rarely crowded.

Another central spot is Fluepapiret. It’s a little urban beach with a nice jetty and even an ice cream kiosk nearby. Both Den Sorte and Fluepapiret fly the Blue Flag too, so water quality is top-notch.

In Kær Vestermark there is Vestermark bad which is an accessible jetty that we also enjoy at times.

Further out, Mommark Marina on Sydals also has a great bathing pier.

And right in the city we have the Sønderborg Harbour Bath next to Hotel Alsik – a cool floating sea-pool in the inner harbour, open to the public in summer with lifeguards on duty. Great for a quick dip or a scenic swim. There are changing facilities on the quay and even a sauna that opens in the colder months. It’s a fantastic addition to the town – basically an outdoor swimming pool in the harbor, where you can swim with a view of Alsik and the waterfront. Read more on the havnebad website.

One of the newest additions to the Sønderborg coastline is the scenic pier by Nordals Resort — a beautifully designed jetty that extends gracefully into the calm waters of the fjord. Whether you’re diving in for a refreshing swim, launching a kayak, or simply enjoying the sea breeze with your feet dangling over the edge, this pier offers a perfect mix of relaxation and activity.
It’s quickly become a favorite for both guests at the resort and locals, serving as a tranquil gateway to the water and a stunning spot to watch the sunset over Nordals.

Stand-Up Paddleboarding (SUP)

Stand-up paddleboarding has exploded in popularity here, and for good reason: we’ve got clear, calm waters and a coastline full of sheltered bays. I personally love to launch my SUP from the Sønderborg marina on the west side and paddle towards the castle – gliding under the Christian X Bridge or along the waterfront on a calm morning is just magical.

If you already have a board, you’ll find plenty of places to get on the water. If not, no problem:

• Sønderborg Yacht Club (SYC) offers SUP meetups and instruction every other Wednesday during the season. (Check the SUP Board Sønderborg facebook group)
• Aquative rents inflatable SUPs and delivers within 30 km.
• Mommark Marina rents out SUP boards and sea kayaks during summer.

Whether you go with a club or a rental, SUP is a must-try here. It’s hard to beat the feeling of peacefully floating over Sønderborg’s clear waters.

Kayaking on Alssund

If sitting down inside a vessel is more your style, kayaking is hugely popular in Sønderborg. You can paddle along the coastline of Als, up the Flensburg Fjord, or around coves and inlets, often in calm conditions.

If you live here or stay for a while, consider joining the Sønderborg Kayak Club. We did their beginner’s course and loved it – and once you’re a member, you can take out club boats and paddle anytime.

We’ve written about the kayak club before – click the link if you’re curious about what the course is like.

Even if you’re just visiting, guided kayak tours are sometimes available and highly recommended for a relaxing paddle under the bridges and along the old harbor.

Sailing Trips & The Bike Ferry

Given our location on the Flensburg Fjord, sailing is in the local DNA. One of the classic adventures is sailing from Sønderborg to Flensburg – a gorgeous route past lighthouses and across the border.

Not a sailor? Try the summer bicycle ferry between Egernsund and Flensburg – you can bring your bike, cross the fjord, and spend a day exploring Germany before ferrying back. It’s a charming summer experience that runs on weekends in peak season.

When they were fixing the Sønderborg bridge in 2021 we could take the bike and pedestrian ferry across for free.

Day Trips with the Fedora Ferry

If you’re looking to get out on the water without doing the paddling yourself, the historic ferry MS Feodora II offers a scenic and relaxed way to explore life along the Flensburg Fjord. The ferry runs a summer route between Sønderborg and Langballigau in Germany, typically from late June through August.

The crossing takes about one hour, and along the way you’ll enjoy beautiful views of the fjord, peaceful coastal villages, and the rolling landscapes of the Danish-German border region.

There are a few important things to note:

• Valid travel documents are required. You must show your passport when boarding, and non-EU citizens need a valid Schengen visa – this also applies to children.
• The ferry departs at 11:00 from Langballigau, which is Feodora II’s home harbor.
• At 15:00, it returns from Sønderborg, departing from the quay next to the harbor office. (Check schedule)
• In case of strong easterly winds or stormy weather, sailings may be cancelled.
• If you’re heading back to Sønderborg after the trip, you can either bring your bike onboard or use public bus transport via Flensburg.

There’s both indoor and outdoor seating onboard, and snacks available – making it a perfect summer outing for families, couples, or anyone who wants to see Sønderborg from the water.

For the latest schedule and ticket information, visit hk-reederei.de.

Windsurfing & Kitesurfing at Kegnæs

For adrenaline lovers, Kegnæs is the place to be. The stretch around Drejby and Lillehav is a top destination for windsurfing and kitesurfing.

It’s popular with both beginners and experienced riders – and there’s even a surf school at Drejby Strand Camping if you want lessons or need to rent gear.

Even if you don’t surf, the action is fun to watch – especially with a coffee from the café next door.

Other Local Water Clubs

If you’re into more than just swimming and paddling, Sønderborg is home to several active water sports clubs that welcome newcomers and visitors alike. Whether you’re interested in rowing, diving, or fishing, there’s likely a local community you can plug into.

Sønderborg Roklub
Founded in 1910, Sønderborg’s rowing club is one of the town’s oldest and most iconic. Their boathouse sits right on the Alssund, and members row both competitively and recreationally. The club is open to all ages and runs beginner sessions each spring. If you’ve ever wanted to glide through the Alssund at sunrise—this is the place.

Deutscher Ruderverein Sønderborg
Yes, there’s also a German-speaking rowing club! It’s a lovely way to connect across cultures (and languages) on the water.

Sønderborg Sportsdykkerklub
For those curious about the world below the surface, the local diving club offers training and excursions for both beginners and experienced divers. They explore everything from shallow coastal dives to deeper wrecks in the area, and the club is part of the Danish Sport Diver Association. Equipment and courses are available through the club.

Sportsfiskerforeningen Als
Prefer staying above water with a rod in hand? The local sports fishing club is active around the island, organizing fishing trips, competitions, and community events. Whether you’re into sea trout fishing in Alssund or relaxed weekend casting from the shore, this is the go-to group for anglers.