[{"data":1,"prerenderedAt":303},["ShallowReactive",2],{"leaderboard-total":3,"spot-seo-port-davey-marine-reserve-general-swimming-diving-area":9,"spot-port-davey-marine-reserve-general-swimming-diving-area":51},{"entries":4,"total":5,"period":6,"type":7,"generated_at":8},[],0,"all_time","reports","2026-10-03T06:32:05.526386Z",{"title":10,"description":11,"canonical_url":12,"og_image":13,"structured_data":14,"breadcrumbs":44},"Snorkeling Conditions at Port Davey Marine Reserve (general swimming\u002Fdiving area) - How's the Spot","Check snorkeling conditions at Port Davey Marine Reserve (general swimming\u002Fdiving area), Tasmania. Excellent conditions, water 12.8°C, waves 0.37m","https:\u002F\u002Fhowsthespot.com\u002Fspots\u002Fport-davey-marine-reserve-general-swimming-diving-area","https:\u002F\u002Fhowsthespot.com\u002Fog-default.png",[15,28],{"@context":16,"@type":17,"name":18,"description":19,"url":12,"geo":20,"address":24},"https:\u002F\u002Fschema.org","Place","Port Davey Marine Reserve (general swimming\u002Fdiving area)","Port Davey Marine Reserve is a truly unique snorkeling destination where dark, tannin-rich freshwater from ancient rainforests sits as a distinct layer atop incoming Southern Ocean tidal saltwater....",{"@type":21,"latitude":22,"longitude":23},"GeoCoordinates",-43.320067,145.9135,{"@type":25,"addressRegion":26,"addressCountry":27},"PostalAddress","Tasmania","Australia",{"@context":16,"@type":29,"name":30,"description":11,"url":12,"breadcrumb":31},"WebPage","Snorkeling Conditions at Port Davey Marine Reserve (general swimming\u002Fdiving area)",{"@context":16,"@type":32,"itemListElement":33},"BreadcrumbList",[34,39,42],{"@type":35,"position":36,"name":37,"item":38},"ListItem",1,"Home","https:\u002F\u002Fhowsthespot.com",{"@type":35,"position":40,"name":26,"item":41},2,"https:\u002F\u002Fhowsthespot.com\u002Fexplore?region=tasmania",{"@type":35,"position":43,"name":18,"item":12},3,[45,47,49],{"label":37,"href":46},"\u002F",{"label":26,"href":48},"\u002Fexplore?region=tasmania",{"label":18,"href":50},"\u002Fspots\u002Fport-davey-marine-reserve-general-swimming-diving-area",{"id":52,"name":18,"slug":53,"latitude":22,"longitude":23,"description":54,"difficulty":55,"image_url":56,"status":57,"tide_constituents":58,"hazard_entries":109,"access_info_structured":243,"area_boundary":56,"routes":56,"created_at":250,"updated_at":251,"today_conditions":252,"today_verdict_view":273,"images":299,"submitted_by":300,"region_name":26,"verification_status":302,"verified_at":56,"disputed":269,"verifier_count":5,"last_verified_display_name":56},"9565b605-ccdc-4659-bc6b-6bf087130d6c","port-davey-marine-reserve-general-swimming-diving-area","Port Davey Marine Reserve is a truly unique snorkeling destination where dark, tannin-rich freshwater from ancient rainforests sits as a distinct layer atop incoming Southern Ocean tidal saltwater. This rare phenomenon, known as a \"meromictic\" estuary, creates spectacular underwater visibility and unusual light effects — the dark tea-coloured lens actually absorbs sunlight, making the deeper saltwater layer crystal clear. Snorkelers float through a surreal world where giant bull kelp forests and colourful sponge gardens thrive in the bathymetric channel, while the surrounding Southwest National Park — a UNESCO Wilderness World Heritage Area — remains roadless and reachable only by boat, light plane or multi-day hike, offering a truly pristine wilderness immersion.","intermediate",null,"published",{"name":59,"amplitude":75,"phase":91,"latitude":22,"model":107,"epoch":108},[60,61,62,63,64,65,66,67,68,69,70,71,72,73,74],"2N2","J1","K1","K2","M2","M4","MF","MM","N2","O1","P1","Q1","S1","S2","T2",[76,77,78,79,80,81,82,83,84,85,86,87,88,89,90],0.005918274713902842,0.009352495258318211,0.1863122224847943,0.02392143685287278,0.08475300615640224,0.001347743691767292,0.009403537057817761,0.004344241247630605,0.02470759560865805,0.13470897821088967,0.05854453857668474,0.032743563683589196,0.007938060907409476,0.08437381515507233,0.0075265793761479525,[92,93,94,95,96,97,98,99,100,101,102,103,104,105,106],241.15146760154948,286.27764481999037,269.423791057631,132.199332172041,11.669505073391832,69.69627081916997,171.8562376618778,181.55382787561336,294.7544147627872,248.83100653996786,265.14318640198564,235.52485909904442,39.303890180004295,126.87995039244572,146.28150377596296,"EOT20","1992-01-01T00:00:00Z",[110,116,121,125,131,135,138,141,144,147,150,153,156,159,162,165,168,171,174,177,180,183,186,189,192,195,198,201,204,207,210,213,216,219,222,225,228,231,234,237,240],{"name":111,"description":112,"severity":113,"season_start":114,"season_end":115},"Southern Ocean Swell","Port Davey is open to the Southern Ocean; long-period swell can enter the outer harbour even in calm conditions, creating surge around rocky edges and sea caves.","warning",4,10,{"name":117,"description":118,"severity":119,"season_start":36,"season_end":120},"Remote Wilderness Isolation","No roads, no settlements, no mobile coverage for hundreds of kilometres. Rescue is hours or days away. Self-sufficiency and EPIRB are essential.","danger",12,{"name":122,"description":123,"severity":113,"season_start":124,"season_end":115},"Cold Water Temperature","Water temperatures rarely exceed 12–14°C even in summer; cold shock and hypothermia are real risks without appropriate wetsuit protection.",5,{"name":126,"description":127,"severity":128,"season_start":129,"season_end":130},"Tannin-Stained Water Visibility","The dark red-brown tannin layer can reduce underwater visibility, especially after rain, making navigation of rocky reefs more challenging.","caution",6,11,{"name":132,"description":133,"severity":119,"season_start":124,"season_end":134},"Strong Westerly Storm Winds","Southwest Tasmania is notorious for sudden violent westerly storms; entry to Port Davey is hazardous in strong W\u002FSW winds with 50-knot squalls possible.",9,{"name":136,"description":137,"severity":119,"season_start":56,"season_end":56},"Remote wilderness location","Extreme isolation — no immediate medical facilities or rescue services. Emergency evacuation is difficult and slow.",{"name":139,"description":140,"severity":113,"season_start":36,"season_end":120},"Cold water temperatures","Water temperatures rarely exceed 12-14°C even in summer, requiring thick wetsuits and experience in cold-water snorkeling.",{"name":142,"description":143,"severity":128,"season_start":36,"season_end":120},"Tannin-stained low visibility","The dark freshwater layer reduces surface visibility significantly, disorienting snorkelers who are not accustomed to low-light underwater conditions.",{"name":145,"description":146,"severity":113,"season_start":36,"season_end":120},"Unpredictable weather and swell","Southwest Tasmania experiences rapidly changing weather with strong winds and swells that can make the bay hazardous.",{"name":148,"description":149,"severity":113,"season_start":56,"season_end":56},"Strong winds and swell","Exposed to the Roaring Forties westerlies. Sudden weather changes can create hazardous sea conditions, especially near the Breaksea Islands entrance.",{"name":151,"description":152,"severity":128,"season_start":56,"season_end":56},"Isolated tidal currents","Tidal movement through the narrow entrance channels can create strong currents. Snorkel only on slack tide in designated areas.",{"name":154,"description":155,"severity":113,"season_start":56,"season_end":56},"Variable weather and sudden storms","South West Tasmania is notorious for rapidly changing weather. Westerly gales, heavy rain, and fog can roll in without warning, making boat\u002Fkayak travel dangerous.",{"name":157,"description":158,"severity":113,"season_start":56,"season_end":56},"Strong tidal currents at entrance","The entrance between Point St. Vincent and Point Hicks experiences strong tidal flows where tannin freshwater meets ocean saltwater, creating unpredictable currents.",{"name":160,"description":161,"severity":128,"season_start":56,"season_end":56},"Limited visibility in tannin-stained water","The tannin-rich freshwater layer reduces underwater visibility, especially near river mouths and after heavy rain, making navigation and spotting hazards difficult.",{"name":163,"description":164,"severity":119,"season_start":36,"season_end":120},"Remote wilderness conditions","Extremely remote — no roads, towns, phone reception, or emergency services. Rescue is difficult and slow.",{"name":166,"description":167,"severity":113,"season_start":129,"season_end":134},"Roaring Forties weather","Exposed to strong westerly winds and rapidly-changing conditions common to the Roaring Forties latitude. Sudden storms can develop.",{"name":169,"description":170,"severity":128,"season_start":36,"season_end":120},"Limited visibility in tannin-stained waters","The dark tannin layer in Bathurst Harbour restricts sunlight and visibility to the top few metres, disorienting snorkelers.",{"name":172,"description":173,"severity":119,"season_start":36,"season_end":120},"Tannin Blackout Layer","The top 5m of freshwater is stained dark by tannins, reducing visibility to near-zero. Snorkelers must descend through this 'ink layer' to reach clear saltwater below.",{"name":175,"description":176,"severity":119,"season_start":36,"season_end":120},"Remote Wilderness Access","Extreme remoteness with no nearby medical facilities. Emergency evacuation is hours or days away. Only experienced, self-sufficient snorkelers should attempt.",{"name":178,"description":179,"severity":113,"season_start":129,"season_end":130},"Unpredictable Southern Ocean Swell","Exposed areas near the mouth of Port Davey can receive sudden large swells from the Southern Ocean, especially outside the shelter of the Breaksea Islands.",{"name":181,"description":182,"severity":119,"season_start":36,"season_end":120},"Remote Location","Extreme remoteness with no immediate medical facilities. Emergency evacuation is very difficult and slow.",{"name":184,"description":185,"severity":113,"season_start":36,"season_end":120},"Unpredictable Weather & Swells","Southern Ocean weather can change rapidly with sudden storms, strong winds, and large swells making conditions hazardous.",{"name":187,"description":188,"severity":113,"season_start":36,"season_end":120},"Strong Tidal Currents","Powerful tidal flows through the narrow entrance channels of Port Davey can create dangerous conditions for swimmers.",{"name":190,"description":191,"severity":128,"season_start":36,"season_end":120},"Limited Visibility from Tannin-stained Water","The tea-coloured freshwater layer from rainforest rivers can reduce surface visibility, though clearer saltwater lies beneath.",{"name":193,"description":194,"severity":119,"season_start":124,"season_end":134},"Severe Weather & Exposed Waters","The reserve faces the volatile Southern Ocean. Exposed waters and severe weather create highly dangerous conditions for boating and snorkeling. Over 30 shipwrecks recorded between Cox Bight and Low Rocky Point.",{"name":196,"description":197,"severity":113,"season_start":56,"season_end":56},"Extreme Remoteness","No roads lead to Port Davey. Access is by 85 km hike, long boat voyage, or small plane. Emergency services are hours or days away, making self-reliance critical.",{"name":199,"description":200,"severity":113,"season_start":56,"season_end":56},"Low Water Temperature","Southern Ocean waters remain extremely cold year-round (8-14°C), requiring thick wetsuits (5-7mm) and posing hypothermia risk even in summer.",{"name":202,"description":203,"severity":113,"season_start":56,"season_end":56},"Isolated Snorkeling Conditions","No on-site facilities, ranger stations, or lifeguards. Snorkelers must be fully self-sufficient with all gear, food, water, and emergency equipment.",{"name":205,"description":206,"severity":128,"season_start":129,"season_end":115},"Poor Visibility in Freshwater Layer","A shallow lens of dark tannin-stained freshwater from rainforest rivers sits atop the saltwater, dramatically reducing surface visibility after heavy rain.",{"name":208,"description":209,"severity":113,"season_start":36,"season_end":120},"Shifting Weather","South West Tasmania is notorious for violent, rapidly changing weather including gale-force winds, heavy rain, and sudden fog that can make boat travel hazardous.",{"name":211,"description":212,"severity":113,"season_start":36,"season_end":120},"Variable Weather & Swells","South West Tasmania is notorious for sudden violent weather changes, including gale-force winds and large ocean swells that can render the area unsafe within minutes.",{"name":214,"description":215,"severity":128,"season_start":36,"season_end":120},"Tannin Layer Disorientation","The dark reddish-brown freshwater surface layer (up to 2m deep) dramatically reduces surface visibility and can cause disorientation — snorkelers may lose their bearings against the dark water.",{"name":217,"description":218,"severity":113,"season_start":36,"season_end":120},"Tannin-stained black water (low visibility)","The top 5 metres of freshwater are stained dark by tannins from Button Grass plains, creating near-zero visibility. Divers must descend below this layer (5+ m) to find clear saltwater.",{"name":220,"description":221,"severity":119,"season_start":129,"season_end":134},"Southern Ocean swell and weather","Port Davey opens to the full fury of the Southern Ocean. Strong winds, large swell, and sudden weather changes can make conditions hazardous, especially near the entrance channel.",{"name":223,"description":224,"severity":119,"season_start":56,"season_end":56},"Extreme Remote Access","No roads lead to Port Davey. Access is via 85 km hike, light plane, or long boat voyage. Emergency evacuation is extremely difficult and delayed.",{"name":226,"description":227,"severity":119,"season_start":56,"season_end":56},"Variable Weather & Swell","The South West coast is exposed to relentless Southern Ocean weather. Sudden changes in wind, rain, and swell can occur without warning, making boat and snorkel conditions hazardous.",{"name":229,"description":230,"severity":128,"season_start":56,"season_end":56},"Tannin Stained Low Visibility","The dark tannin-stained freshwater layer reduces surface visibility significantly, requiring divers to descend below the halocline for clearer views. Can be disorienting for snorkelers.",{"name":232,"description":233,"severity":113,"season_start":56,"season_end":56},"Extreme tannin-stained surface water","Top 5 m of the water column is dark as ink from dissolved organic tannins, reducing visibility to near-zero and disorienting snorkelers.",{"name":235,"description":236,"severity":113,"season_start":129,"season_end":134},"Unpredictable Southern Ocean weather","Sudden weather changes, strong winds, and heavy swells can sweep into the inlet from the Southern Ocean, particularly near the Breaksea Islands.",{"name":238,"description":239,"severity":128,"season_start":56,"season_end":56},"Tannin-stained low visibility in top layer","The top 5 metres of the water column is stained dark by tannins, reducing surface visibility to near zero. Requires comfort with limited light penetration.",{"name":241,"description":242,"severity":113,"season_start":56,"season_end":56},"Strong tidal currents in Bathurst Narrows","Tidal flows between Bathurst Harbour and the Southern Ocean can create strong currents, especially through the narrow channels.",{"directions":244,"parking":245,"facilities":246,"fees":248,"access_method":249},"Port Davey is located in the remote South West Wilderness of Tasmania. There are no roads — access is only by private or charter boat from Hobart (approx. 6-8 hours), by light plane landing at Melaleuca airstrip followed by a short boat transfer, or via the 85km South Coast Track multi-day hike. Boat travellers require the relevant nautical chart for Bathurst Channel. Kayak expeditions are possible for experienced paddlers.","No vehicle parking available — there are no roads to Port Davey. Leave vehicles in Hobart or at the Cockle Creek car park (end of the road) if hiking in.",[247],"toilets","A Tasmania Parks Pass is required for entry to Southwest National Park. Some commercial operators charge for boat charters or guided tours. No on-site fee office.","boat","2026-07-27T02:57:52.114249Z","2026-08-04T05:34:24.990805Z",{"verdict":253,"evaluated_at":254,"models":255},"go","2026-10-03T02:18:29.046171Z",[256,262,267],{"model_name":257,"is_favourable":258,"value":259,"threshold":115,"unit":260,"operator":261},"Wind Speed",true,5.68,"kn","lte",{"model_name":263,"is_favourable":258,"value":264,"threshold":265,"unit":266,"operator":261},"Wave Height",0.368,0.5,"m",{"model_name":268,"is_favourable":269,"value":270,"threshold":40,"unit":271,"operator":272},"Visibility",false,1.95,"","gte",{"verdict":253,"rating":274,"evaluated_at":254,"generated_at":254,"source":275,"confidence":276,"visibility":279,"parameters":280,"models_passed":114,"models_total":124},"Excellent","precomputed",{"level":277,"value":278},"High",100,{"score":270,"rating":56,"confidence":56},[281,283,288,291,296],{"name":263,"value":282,"label":56,"unit":266,"favourable":258,"score":43,"optimal_max":265,"marginal_max":36},0.36800000000000005,{"name":284,"value":285,"label":56,"unit":286,"favourable":269,"score":36,"optimal_max":287,"marginal_max":120},"Swell Period",10.9,"s",8,{"name":257,"value":289,"label":56,"unit":260,"favourable":258,"score":43,"optimal_max":115,"marginal_max":290},5.684301475347065,15,{"name":292,"value":293,"label":56,"unit":294,"favourable":258,"score":43,"optimal_max":124,"marginal_max":295},"Precipitation",3.1,"mm",20,{"name":297,"value":56,"label":298,"unit":271,"favourable":258,"score":43,"optimal_max":56,"marginal_max":56},"Tidal Phase","slack",[],{"display_name":301},"Daniel","unverified",1791009187035]