Kasa - Mafia Island
Middle Arch is a site we always make time for at the Poor Knights, and it’s a good one to hit early in the day before other boats crowd the space. Drop in at the northern side, and you’re instantly in the twilight, the arch opening up below you. We love the feeling of being funnelled through, the rock walls rising on either side, often draped with orange jewel anemones. Look up sometimes, and you’ll see the sunlight filtering through the kelp at the shallower parts. You’ll usually find big schools of snapper and kingfish hanging in the current, and we’ve often seen short-tail stingrays cruising the sandy bottom at about 18 meters. The really cool part is the small cave near the southwestern exit. It’s a tight squeeze in, but once you’re inside, there’s an air pocket, and you can surface and hear the shearwaters calling from outside. It’s an ethereal, almost ancient sound, really making you feel connected to this wild place. This site suits divers who appreciate a bit of overhead environment, comfortable navigating through a well-lit arch. Expect to be surrounded by schools of fish, and keep an eye out for those impressive stingrays.
- Location
- Mafia Island, Tanzania, Indian Ocean & East Africa
- Coordinates
- -7.963000, 39.813900
- Type
- cave
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
- Bwejuu Wall (wall)
- Bwejuu Wall (wall)
- Chekechea (reef)
- Chole Reef North (reef)
- Coral Gardens (reef)
- Coral Islands (reef)
- Corinne’s Reef (reef)
- Critters Alley (reef)
- Cryptomania (reef)
- Dindini Wall (wall)
- Hulls Rock (reef)
- Jina Wall (reef)
- Juani North (reef)
- Juani South (wall)
- Kinasi Pass (drift)
Nearest Dive Centres to Kasa
- Action for Oceans Eco Dive - ["PADI"]
- Blue World Diving - ["PADI"]
- Mafia Island Diving ltd - PADI
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
- Green Turtle (Chelonia mydas)
- Allison's Tuna (Thunnus albacares) - Reef Fish
- Whale Shark (Rhincodon typus) - Sharks & Rays
- Stripy (Katsuwonus pelamis) - Reef Fish
- Bigeye tuna (Thunnus obesus) - Reef Fish
- Bullet Mackerel (Auxis thazard) - Reef Fish
- Tuna (Thunnus alalunga) - Reef Fish
- Sperm Whale (Physeter macrocephalus) - Whales & Dolphins
- Tail-spot Squirrelfish (Sargocentron caudimaculatum) - Reef Fish
- Cauliflower coral (Pocillopora verrucosa) - Hard Corals
- Smooth cauliflower coral (Stylophora pistillata) - Hard Corals
- Stony coral (Porites cylindrica) - Hard Corals
- Stony coral (Porites lutea) - Hard Corals
- Larger star coral (Favites pentagona) - Hard Corals
- Staghorn coral (Acropora aspera) - Hard Corals
- Staghorn coral (Acropora listeri) - Hard Corals
- Birdsnest coral (Seriatopora caliendrum) - Hard Corals
- Thin birdsnest coral (Seriatopora hystrix) - Hard Corals
- Staghorn coral (Acropora polystoma) - Hard Corals
- Closed brain coral (Leptoria phrygia) - Hard Corals
Recommended Packing List for Kasa
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