Seamount - Mafia Island

The Gutter at Bass Point is a Sydney classic, and for good reason. We love it because it’s so reliable, even on days when other sites are blown out. The entry off the rocks is a splashy affair, sometimes a bit of a leap depending on the swell, straight into maybe four metres of water. Fin up quickly, then head north. You’ll hit a sizeable rock after a short swim, a kind of underwater landmark that signals the start of the fun. From there, the main channel, our favourite part, opens up, dropping to around 18 metres. It's a rocky bottom, a jumble of boulders and ledges, but the real show is the life tucked into every crevice. We’ve had some incredible encounters here: massive cuttlefish gliding by, sometimes a gang of bull sharks patrolling the deeper sections, and if you’re patient, the elusive Spitlure Frogfish camouflaged perfectly against the rock. It’s a site that rewards slow diving, peering under overhangs for nudibranchs, or scanning the sandy patches for an Oriental flying gurnard fanning its incredible fins. Visibility averages around nine metres, so it’s not always gin-clear, but it’s often good enough to really soak it all in. This is a site for the diver who loves exploring, who doesn't mind a bit of a current, and who gets a thrill from discovering critters.

Location
Mafia Island, Tanzania, Indian Ocean & East Africa
Coordinates
-10.227400, 40.188700
Type
pinnacle

Marine Protected Area: Mangrove

Best Time to Dive in Mafia Island

The warmest water temperatures in Mafia Island occur in January, averaging 28.8°C. The coolest conditions are in December at 28.8°C.

Monthly Water Temperatures

  • January: 28.8°C (air: 27.8°C)
  • February: 28.8°C (air: 28.0°C)
  • March: 28.8°C (air: 27.8°C)
  • April: 28.8°C (air: 27.0°C)
  • May: 28.8°C (air: 26.9°C)
  • June: 28.8°C (air: 26.0°C)
  • July: 28.8°C (air: 25.2°C)
  • August: 28.8°C (air: 25.0°C)
  • September: 28.8°C (air: 25.3°C)
  • October: 28.8°C (air: 26.1°C)
  • November: 28.8°C (air: 27.0°C)
  • December: 28.8°C (air: 27.7°C)

Nearby Dive Sites in Mafia Island

Nearest Dive Centres to Seamount

Marine Life in Mafia Island

Home to 165 recorded species including 94 hard corals, 63 reef fish, 3 sharks & rays, 2 jellyfish, 1 other, 1 whales & dolphins.

Notable Species

Recommended Packing List for Seamount

Based on average water temperature of 28.8°C.

  • Shorty or Rashguard - warm 29°C water needs minimal exposure protection
  • 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

Frequently Asked Questions

What are the typical diving depths and profiles when exploring a seamount?
At the Seamount near Mafia Island, divers typically explore depths starting at 12m down to a maximum of 22m. The dive profile features a beautiful series of outcrops, steep cliffs, gulleys, and sand channels. This makes for an engaging exploration of its pristine coral formations.
What kind of marine life and unique ecosystems can divers expect to encounter at a seamount dive site?
Divers at the Seamount can expect to encounter a vibrant ecosystem covered in pristine coral. Large shoals of fish, including Surgeonfish, Unicorn fish, Red tooth Triggerfish, and Fusiliers, are abundant. Additionally, Tuna and Trevally are often seen passing by, and many interesting critters can be spotted in the cracks of the reef, offering a rich marine life experience.
How challenging is diving at a seamount, especially regarding experience level and potential hazards?
Diving at the Seamount is officially rated as intermediate difficulty. However, with depths starting at 12m and a maximum of 22m, it is described as a great dive for all levels, offering accessible exploration of its beautiful features. Divers should be comfortable with typical reef diving conditions.
What is generally considered the best time of year to dive seamounts for optimal conditions and marine encounters?
Information regarding the best time of year to dive the Seamount for optimal conditions and marine encounters is not provided in the current data. For general guidance on dive seasons, please refer to our When to Dive resource.
What dive certifications or experience levels are typically recommended or required for diving seamounts?
For diving the Seamount, an intermediate experience level is typically recommended. While it's considered a great dive for all levels, especially given its starting depth of 12m, divers should possess the necessary certification and comfort for exploring depths up to 22m.
What are the typical current conditions and visibility like when diving a seamount?
The provided data does not specify the typical current conditions or visibility for diving the Seamount. Divers should always consult with local dive operators for the most up-to-date information on site conditions before planning their dive.