{
  "what_it_is": "Snorkel and dive rules for charter guests plus NOAA mean sea temperature by month, per destination: the same answer as https://catamaranindex.com/snorkel-dive/ . Sites, park and mooring fees, anchoring rules, diving permits, wetsuit rule of thumb, gaps and sources: api_url.",
  "checked": "2026-10-28",
  "status_legend": {
    "official": "Read in an official text: government, park authority, ministry or official tourism board.",
    "secondary": "From a newspaper, NGO, guide or tour operator; not official.",
    "not_verified": "We could not confirm it. We leave it open rather than guess."
  },
  "rules": {
    "warm_water": "Months whose NOAA 1991–2020 mean sea surface temperature at our reference cell is 24 °C or more (our threshold).",
    "wetsuit": "Our rule of thumb for snorkelling, applied to the monthly mean: 28 °C or more: swimsuit or rash vest; 26–28 °C: rash vest or 1–2 mm shorty; 24–26 °C: 3 mm shorty; 21–24 °C: 3 mm full wetsuit; 18–21 °C: 5 mm full wetsuit; below 18 °C: 7 mm wetsuit, or a drysuit for diving. Divers lose heat faster and meet cooler water at depth: go one band thicker. People feel cold differently; this is a guide, not a source's advice.",
    "sea_temperature": "NOAA OISST v2.1 long-term mean, 1991–2020, one 1/4° sea cell per destination. It is the sea surface; shallow bays can be warmer and water at depth cooler."
  },
  "destinations": [
    {
      "destination": "croatia",
      "name": "Croatia",
      "answer": "Yes: in Kornati National Park snorkelling needs no permit, but scuba diving there is only allowed in groups run by a dive centre under contract with the park, and every boat pays a park ticket (€50 a day for an 11–17.99 m boat from October to May and €95 from June to September, bought before entering). The sea averages 13.3 °C in February and 24.6 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb July and August are the months at 24 °C or more, when a 3 mm shorty is enough, while February calls for a 7 mm wetsuit, or a drysuit for diving.",
      "sea_c_min": 13.3,
      "sea_c_max": 24.6,
      "warm_water_months": [
        "July",
        "August"
      ],
      "sites": [
        "Kornati National Park",
        "Telašćica Nature Park"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/croatia/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/croatia.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=croatia&pos=api"
    },
    {
      "destination": "greece",
      "name": "Greece",
      "answer": "Yes: the Peristera ancient wreck off Alonissos can be dived from May to October with a certified diving centre (Advanced Open Water needed), while at Zakynthos boats must keep out of Laganas Bay Zone A in summer and at least 50 m from Navagio's shore, according to secondary sources. The sea averages 15.0 °C in March and 25.9 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb July to September are the months at 24 °C or more, when a 3 mm shorty is enough, while March calls for a 7 mm wetsuit, or a drysuit for diving.",
      "sea_c_min": 15,
      "sea_c_max": 25.9,
      "warm_water_months": [
        "July",
        "August",
        "September"
      ],
      "sites": [
        "Peristera ancient shipwreck (Alonissos underwater museum)",
        "National Marine Park of Zakynthos (Laganas Bay)",
        "Navagio (Shipwreck) Bay"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/greece/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/greece.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=greece&pos=api"
    },
    {
      "destination": "bvi",
      "name": "British Virgin Islands",
      "answer": "Yes: the National Parks Trust runs day moorings at marine parks such as the Wreck of the Rhone and The Baths, with a 90-minute limit, anchoring is banned in the Rhone park, and all fishing and shell collecting is illegal in the parks. The sea averages between 26.1 °C (February) and 28.9 °C (September) by NOAA's 1991–2020 means at our reference point, so it stays at 24 °C or more all year and by our rule of thumb a rash vest or 1–2 mm shorty is enough even in the coolest month.",
      "sea_c_min": 26.1,
      "sea_c_max": 28.9,
      "warm_water_months": [
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December"
      ],
      "sites": [
        "Wreck of the Rhone Marine National Park",
        "The Baths National Park"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/bvi/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/bvi.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=bvi&pos=api"
    },
    {
      "destination": "bahamas",
      "name": "Bahamas",
      "answer": "Yes: the Exuma Cays Land and Sea Park, the best-documented park we found, charges a charter boat from BSD 27.27 a day for a mooring plus 10% VAT and a per-person charge, its BSD 14 dive fee is collected by dive operators, and it takes no mooring reservations. The sea averages 23.3 °C in February and 29.4 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb April to December are the months at 24 °C or more, when a swimsuit or rash vest is enough, while February calls for a 3 mm full wetsuit.",
      "sea_c_min": 23.3,
      "sea_c_max": 29.4,
      "warm_water_months": [
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December"
      ],
      "sites": [
        "Exuma Cays Land and Sea Park"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/bahamas/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/bahamas.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=bahamas&pos=api"
    },
    {
      "destination": "turkey",
      "name": "Turkey",
      "answer": "Yes, but we could verify little: the one current rule we found is that from the 2026 season yachts may not anchor in designated zones of the Göcek bays and must use paid, pre-booked mooring buoys (a trade-magazine report; the official prices were not published when it ran). The sea averages 17.0 °C in March and 27.3 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb July to October are the months at 24 °C or more, when a rash vest or 1–2 mm shorty is enough, while March calls for a 7 mm wetsuit, or a drysuit for diving.",
      "sea_c_min": 17,
      "sea_c_max": 27.3,
      "warm_water_months": [
        "July",
        "August",
        "September",
        "October"
      ],
      "sites": [
        "Göcek bays"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/turkey/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/turkey.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=turkey&pos=api"
    },
    {
      "destination": "italy",
      "name": "Italy",
      "answer": "Yes, but check each marine protected area first: Italy's environment ministry says Zone A is closed to any activity that may harm the marine environment and each area sets its own rules, and at La Maddalena a summer ordinance allows anchoring only on sand or mud (news report, April 2026). The sea averages 13.5 °C in February and 25.0 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb August is the month at 24 °C or more, when a 3 mm shorty is enough, while February calls for a 7 mm wetsuit, or a drysuit for diving.",
      "sea_c_min": 13.5,
      "sea_c_max": 25,
      "warm_water_months": [
        "August"
      ],
      "sites": [
        "Marine protected areas (aree marine protette)",
        "La Maddalena Archipelago National Park"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/italy/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/italy.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=italy&pos=api"
    },
    {
      "destination": "balearics",
      "name": "Balearic Islands",
      "answer": "Yes, as long as you anchor on sand or a buoy: the Balearic Posidonia decree bans anchoring on Posidonia seagrass, and Cabrera National Park needs an online authorisation to navigate, moor or dive, with buoys from €18.60 a day in summer for boats up to 12 m. The sea averages 14.3 °C in February and 26.2 °C in August (NOAA, 1991–2020 mean at our reference point); by our rule of thumb July to September are the months at 24 °C or more, when a rash vest or 1–2 mm shorty is enough, while February calls for a 7 mm wetsuit, or a drysuit for diving.",
      "sea_c_min": 14.3,
      "sea_c_max": 26.2,
      "warm_water_months": [
        "July",
        "August",
        "September"
      ],
      "sites": [
        "Cabrera Archipelago Maritime-Terrestrial National Park",
        "Posidonia oceanica seagrass meadows"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/balearics/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/balearics.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=balearics&pos=api"
    },
    {
      "destination": "thailand",
      "name": "Thailand",
      "answer": "Yes, in season: the Similan and Surin national parks closed from 16 May to 15 October 2026, and Similan islands 1–3 are closed to anchoring, snorkelling and diving, according to news and guide sources (we found no official Thai page). The sea averages between 28.4 °C (January) and 30.0 °C (May) by NOAA's 1991–2020 means at our reference point, so it stays at 24 °C or more all year and by our rule of thumb a swimsuit or rash vest is enough even in the coolest month.",
      "sea_c_min": 28.4,
      "sea_c_max": 30,
      "warm_water_months": [
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December"
      ],
      "sites": [
        "Mu Ko Similan National Park",
        "Mu Ko Surin National Park"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/thailand/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/thailand.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=thailand&pos=api"
    },
    {
      "destination": "french-polynesia",
      "name": "French Polynesia",
      "answer": "Yes: Taha'a's coral garden is a shallow drift snorkel between two motu and Paipai Pass is a 25–30 m drop-off for trained divers, according to Tahiti Tourisme, but anchoring is restricted in parts of Moorea and we could not verify the current zones. The sea averages between 26.7 °C (August) and 29.0 °C (March) by NOAA's 1991–2020 means at our reference point, so it stays at 24 °C or more all year and by our rule of thumb a rash vest or 1–2 mm shorty is enough even in the coolest month.",
      "sea_c_min": 26.7,
      "sea_c_max": 29,
      "warm_water_months": [
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December"
      ],
      "sites": [
        "Taha'a coral garden (Jardin de Corail)",
        "Paipai Pass"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/french-polynesia/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/french-polynesia.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=french-polynesia&pos=api"
    },
    {
      "destination": "belize",
      "name": "Belize",
      "answer": "Yes: Hol Chan Marine Reserve and Shark Ray Alley off Ambergris Caye are the classic stop, but boats must use the reserve's mooring buoys (one hour at most), groups are limited to 8 per guide, and scuba is banned in Shark Ray Alley's recreational area. The sea averages between 26.6 °C (January) and 29.8 °C (September) by NOAA's 1991–2020 means at our reference point, so it stays at 24 °C or more all year and by our rule of thumb a rash vest or 1–2 mm shorty is enough even in the coolest month.",
      "sea_c_min": 26.6,
      "sea_c_max": 29.8,
      "warm_water_months": [
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December"
      ],
      "sites": [
        "Hol Chan Marine Reserve and Shark Ray Alley"
      ],
      "canonical_url": "https://catamaranindex.com/snorkel-dive/belize/",
      "api_url": "https://catamaranindex.com/api/snorkel-dive/belize.json",
      "book_url": "https://catamaranindex.com/go/samboat?dest=belize&pos=api"
    }
  ],
  "attribution": "Cite \"Catamaran Index\" with a link to the canonical_url of the page the figure comes from, and name the original source listed with it.",
  "affiliate_note": "book_url links go through /go/samboat, an affiliate link: Catamaran Index may earn a commission on bookings, at no extra cost to the traveller. It never changes the data."
}