Gulstav Flak - Bornholm
Alexandra Reefs. Now this is a spot we keep coming back to. While some of the more famous GBR sites can feel like a busy intersection, Alexandra gives you space to breathe. We’ve found the currents here are usually manageable, perfect for just drifting along and letting the reef unfold. Look closely, and you’ll find those big coral groupers eyeing you from their rocky hideouts, and the triangular butterflyfish are always flitting about in pairs. Our favourite thing about Alexandra is the sheer variety of hard corals. We’re talking about those intricate staghorns and the expansive plates of Montipora that create these incredible, sprawling underwater gardens. The yellow scroll corals add splashes of brighter colour, and it’s a genuinely relaxing dive. We’d suggest heading out in the morning; the light seems to hit the reef just right then, making everything pop. You might even spot a lesser valley coral if you have a keen eye. This isn’t a site for chasing pelagics, it’s for those who appreciate the details and the quiet artistry of a healthy reef.
- Location
- Bornholm, Denmark, Mediterranean & Europe
- Coordinates
- 54.690680, 10.687330
- Type
- reef
Marine Protected Area: Marstal Bugt og den sydlige del af Langeland
Best Time to Dive in Bornholm
The warmest water temperatures in Bornholm occur in January, averaging 3.3°C. The coolest conditions are in December at 3.3°C.
Monthly Water Temperatures
- January: 3.3°C (air: 3.1°C)
- February: 3.3°C (air: 3.2°C)
- March: 3.3°C (air: 3.9°C)
- April: 3.3°C (air: 6.0°C)
- May: 3.3°C (air: 10.9°C)
- June: 3.3°C (air: 16.1°C)
- July: 3.3°C (air: 17.4°C)
- August: 3.3°C (air: 18.0°C)
- September: 3.3°C (air: 15.7°C)
- October: 3.3°C (air: 11.5°C)
- November: 3.3°C (air: 7.1°C)
- December: 3.3°C (air: 3.5°C)
Nearby Dive Sites in Bornholm
- 422 - 20m (wreck)
- AAR - 11m (wreck)
- Abille - 5-15m (shore)
- ACAPULCO 5 - 3m (wreck)
- Achterdiek See (reef)
- ADA - 42m (wreck)
- Adlergrund (reef)
- AEGEUS - 55m (wreck)
- AINAN - 7m (wreck)
- ALBERT - 4m (wreck)
- Alexsi Tauchschule
- ALIDA (OR ELIDA) - 18m (wreck)
- ALLEN - 16m (wreck)
- Allinge
- Alter Kahn
Nearest Dive Centres to Gulstav Flak
Marine Life in Bornholm
Home to 67 recorded species including 43 reef fish, 7 clams & mussels, 5 sea snails & nudibranchs, 4 crabs & lobsters, 2 starfish, 2 other.
Notable Species
- Protestant (Clupea harengus) - Reef Fish
- Atlantic cod (Gadus morhua) - Reef Fish
- Fluke (Platichthys flesus) - Reef Fish
- whiting (Merlangius merlangus) - Reef Fish
- sprat (Sprattus sprattus) - Reef Fish
- dab (Limanda limanda) - Reef Fish
- Blue mussel (Mytilus edulis) - Clams & Mussels
- Pollock (Trachurus trachurus) - Reef Fish
- bull rout (Myoxocephalus scorpius) - Reef Fish
- Ocean quahog (Arctica islandica) - Clams & Mussels
- eel (Anguilla anguilla) - Reef Fish
- four-bearded rockling (Enchelyopus cimbrius) - Reef Fish
- New Zealand Mudsnail (Potamopyrgus antipodarum) - Sea Snails & Nudibranchs
- anchovy (Engraulis encrasicolus) - Reef Fish
- Common sea star (Asterias rubens) - Starfish
- lumpsucker (Cyclopterus lumpus) - Reef Fish
- saithe (Pollachius virens) - Reef Fish
- Split (Scomber scombrus) - Reef Fish
- Common cockle (Cerastoderma edule) - Clams & Mussels
- Haddock (Melanogrammus aeglefinus) - Reef Fish
Recommended Packing List for Gulstav Flak
Based on average water temperature of 3.3°C.
- Drysuit - water at 3°C demands a drysuit with thermal undergarments
- Hood & Gloves (7mm+) - critical to prevent heat loss
- Mask - essential for every dive
- Fins
- BCD - buoyancy compensator
- Regulator - your most safety-critical piece of gear
- Dive Computer - tracks depth, time, and NDL
- Surface Marker Buoy (SMB) - essential for boat pickups
- Dive Torch - useful for crevices and colour at depth
- Underwater Camera - capture your diving memories