Snorkelling and diving from a charter boat: sites, rules and sea temperature by destination
Sea temperature by month (NOAA), wetsuit guide, snorkel and dive sites, park fees and anchoring rules for 10 yacht charter destinations. Checked 28 Oct 2026.
Warm all year
BVI, Thailand, French Polynesia, Belize
Sea ≥ 24 °C every month (NOAA)
Source: NOAA PSL (NOAA/NCEI OISST v2.1), checked
Mediterranean
Jul–Sep
About when the sea reaches 24 °C (our mark)
No anchoring
Posidonia, Rhone, Hol Chan
Official rules
Checked
28 Oct 2026
10 destinations
You can snorkel and dive from a charter boat in all 10 destinations we cover, but the rules are local: national and marine parks charge boats a fee or require a permit (Kornati, Cabrera, the Exuma park, the BVI parks), anchoring is banned or restricted in places to protect seagrass, coral and wrecks (Posidonia in the Balearics, the Rhone wreck in the BVI, Hol Chan in Belize), and scuba in some parks is only allowed with an approved dive centre. By NOAA's 1991–2020 averages the sea stays at 24 °C or more all year in the BVI, Thailand, French Polynesia and Belize, while Mediterranean destinations range from 13.3 °C in late winter to 27.3 °C in August at our reference points, so by our rule of thumb a 3 mm suit or less is enough there only from about July to September (October in Turkey, August alone in Italy).
Checked 28 Oct 2026. Sea temperatures are NOAA's 1991–2020 monthly means; the warm-water mark and the wetsuit guide are our rules of thumb. Each destination page labels every fact official, secondary or not verified. The one-line summaries below are ours.
Snorkelling and diving by charter boat: every destination compared
| Destination | Warm water (≥24 °C) | Sea, coolest–warmest | Sites we could document | Rule to know | Boats |
|---|---|---|---|---|---|
| Croatia | July and August | 13.3–24.6 °C | Kornati National Park; Telašćica Nature Park | Kornati: park ticket per boat; scuba only with a contracted dive centre (official) | SamBoat |
| Greece | July to September | 15.0–25.9 °C | Peristera ancient shipwreck (Alonissos underwater museum); National Marine Park of Zakynthos (Laganas Bay); Navagio (Shipwreck) Bay | Peristera wreck: certified dive centre, AOW (official); Zakynthos zones (secondary) | SamBoat |
| British Virgin Islands | All year | 26.1–28.9 °C | Wreck of the Rhone Marine National Park; The Baths National Park | NPT day moorings, 90 min; no anchoring in the Rhone park (official) | SamBoat |
| Bahamas | April to December | 23.3–29.4 °C | Exuma Cays Land and Sea Park | Exuma park: mooring fee by length + per person, no reservations (official) | SamBoat |
| Turkey | July to October | 17.0–27.3 °C | Göcek bays | Göcek: paid buoy zones from 2026, no anchoring there (secondary) | SamBoat |
| Italy | August | 13.5–25.0 °C | Marine protected areas (aree marine protette); La Maddalena Archipelago National Park | Each marine protected area has its own rules; Zone A closed (official) | SamBoat |
| Balearic Islands | July to September | 14.3–26.2 °C | Cabrera Archipelago Maritime-Terrestrial National Park; Posidonia oceanica seagrass meadows | No anchoring on Posidonia; Cabrera needs a permit (official) | SamBoat |
| Thailand | All year | 28.4–30.0 °C | Mu Ko Similan National Park; Mu Ko Surin National Park | Similan and Surin closed mid-May to mid-October (secondary) | SamBoat |
| French Polynesia | All year | 26.7–29.0 °C | Taha'a coral garden (Jardin de Corail); Paipai Pass | Anchoring restricted in parts of Moorea; zones not verified | SamBoat |
| Belize | All year | 26.6–29.8 °C | Hol Chan Marine Reserve and Shark Ray Alley | Hol Chan: use buoys, 1 hour, 8 per guide (official) | SamBoat |
Sea temperature by month (°C)
NOAA OISST v2.1, 1991–2020 mean sea surface temperature at one reference cell per destination (NOAA PSL (NOAA/NCEI OISST v2.1), checked 28 Oct 2026), rounded to whole degrees here (one decimal on each destination page). Bold = 24 °C or more, our warm-water mark.
| Area | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Croatia | 14 | 13 | 14 | 15 | 18 | 22 | 24 | 25 | 23 | 21 | 19 | 16 |
| Greece | 16 | 15 | 15 | 16 | 19 | 22 | 25 | 26 | 25 | 23 | 20 | 18 |
| BVI | 26 | 26 | 26 | 27 | 27 | 28 | 28 | 29 | 29 | 29 | 28 | 27 |
| Bahamas | 24 | 23 | 24 | 25 | 26 | 28 | 29 | 29 | 29 | 28 | 26 | 25 |
| Turkey | 18 | 17 | 17 | 18 | 20 | 23 | 26 | 27 | 26 | 24 | 22 | 20 |
| Italy | 14 | 14 | 14 | 15 | 17 | 21 | 24 | 25 | 23 | 20 | 17 | 15 |
| Balearic Islands | 15 | 14 | 15 | 16 | 18 | 22 | 25 | 26 | 25 | 22 | 19 | 16 |
| Thailand | 28 | 29 | 29 | 30 | 30 | 30 | 30 | 30 | 29 | 29 | 29 | 29 |
| French Polynesia | 29 | 29 | 29 | 29 | 28 | 28 | 27 | 27 | 27 | 27 | 28 | 28 |
| Belize | 27 | 27 | 27 | 28 | 29 | 29 | 29 | 30 | 30 | 29 | 28 | 27 |
What wetsuit do I need? Our rule of thumb
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.
| Mean sea temperature | Our rule of thumb for snorkelling |
|---|---|
| 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 |
Four rules that catch charter crews
- Seagrass: in the Balearics, Decree 25/2018 bans anchoring on Posidonia oceanica; anchor on sand or use a buoy (Balearics).
- Mooring time limits: BVI National Parks Trust moorings are day-use with a 90-minute limit, and Hol Chan in Belize allows one hour (BVI, Belize).
- Park tickets per boat: Kornati charges every vessel by length, and about twice as much if you buy the ticket inside the park (Croatia); the Exuma park charges by length plus a per-person fee (Bahamas).
- Scuba with a dive centre: in Kornati scuba is only allowed with a dive centre under contract with the park, and the Peristera wreck only with a certified centre (Croatia, Greece).
See boats for rent
See catamarans for rent on SamBoat
Check the park rules for your area before you book. We may earn a commission if you book through our links, at no extra cost to you (disclosure).
Sources
- NOAA PSL (NOAA/NCEI OISST v2.1): NOAA High-resolution Blended Analysis: OISST v2.1 long-term mean monthly sea surface temperature, 1991–2020 (sst.mon.ltm.1991-2020.nc) (official), checked 28 Oct 2026.
- Kornati National Park (JU NP Kornati): Ronjenje i snorkeling (diving and snorkelling) (official), checked 28 Oct 2026.
- Kornati National Park (JU NP Kornati): Pravila ponašanja (rules of conduct) (official), checked 28 Oct 2026.
- Kornati National Park (JU NP Kornati): Cjenik naknada i usluga za 2026. godinu (2026 price list) (official), checked 28 Oct 2026.
- gov.hr (Croatian government portal): Diving (official), checked 28 Oct 2026.
- Visit Greece (Greek National Tourism Organisation): Alonnisos underwater museum: the ancient shipwreck of Peristera (official), checked 28 Oct 2026.
- National Parks Trust of the Virgin Islands: Park tickets & Marine Conservation Permit: marine park guidelines (official), checked 28 Oct 2026.
- Bahamas National Trust: Exuma Cays Land and Sea Park (ECLSP) fees (official), checked 28 Oct 2026.
- MASE (Italian Ministry of the Environment): Aree marine protette (official), checked 28 Oct 2026.
- Govern de les Illes Balears (CAIB): Decreto 25/2018, de 27 de julio, sobre la conservación de la Posidonia oceanica en las Illes Balears (official), checked 28 Oct 2026.
- Govern de les Illes Balears (CAIB): Autorización para navegar, fondear o bucear en el Parque Nacional Marítimo-Terrestre del Archipiélago de Cabrera (official), checked 28 Oct 2026.
- MITECO (Spanish Ministry for the Ecological Transition), National Parks network: Archipiélago de Cabrera: usos compatibles (official), checked 28 Oct 2026.
- Tahiti Tourisme: Jardin de corail, Taha'a (official), checked 28 Oct 2026.
- Tahiti Tourisme: Diving in Taha'a (official), checked 28 Oct 2026.
- DPAM, Government of French Polynesia: Création d'une zone d'interdiction de mouillage à Papetoai (official), checked 28 Oct 2026.
- Belize Fisheries Department: Fisheries Dept – Hol Chan (official), checked 28 Oct 2026.
- ARCHELON (Sea Turtle Protection Society of Greece): Collisions of boats with sea turtles continue at Zakynthos National Marine Park (secondary, not official), checked 28 Oct 2026.
- To Vima (newspaper): Zakynthos: Navagio beach access curbs extended through 2026 (secondary, not official), checked 28 Oct 2026.
- Yachting Magazine (Turkey): Smart buoys, not anchor: new mooring rules in Göcek (secondary, not official), checked 28 Oct 2026.
- L'Unione Sarda (newspaper): La Maddalena, stretta su navigazione e ancoraggi per tutelare l'ambiente marino (secondary, not official), checked 28 Oct 2026.
- Thairath (newspaper): Similan and Surin close for five months (secondary, not official), checked 28 Oct 2026.
- Aster of Asia (tour operator): Similan Islands 2026: opening on 15 October (secondary, not official), checked 28 Oct 2026.
- Thai Marine Guide: Thai Marine Guide – restricted areas (secondary, not official), checked 28 Oct 2026.
- The San Pedro Sun (newspaper): New park fee goes into effect at Hol Chan Marine Reserve (secondary, not official), checked 28 Oct 2026.
Method: methodology. Data: JSON.
How to read the labels
- [Secondary source]: From a newspaper, NGO, guide or tour operator; not official.
- [Not verified]: We could not confirm it. We leave it open rather than guess.
- No label: Read in an official text: government, park authority, ministry or official tourism board.
Sea temperatures are NOAA's; the wetsuit column, the 24 °C warm-water mark and any sum or comparison are ours and say so. Park rules change and some are seasonal: check with the park, your charter base or a local dive centre before you go.
Snorkel and dive guides by destination
Croatia · Greece · British Virgin Islands · Bahamas · Turkey · Italy · Balearic Islands · Thailand · French Polynesia · Belize
Frequently asked questions
Can you snorkel and dive from a charter yacht or catamaran?
You can snorkel and dive from a charter boat in all 10 destinations we cover, but the rules are local: national and marine parks charge boats a fee or require a permit (Kornati, Cabrera, the Exuma park, the BVI parks), anchoring is banned or restricted in places to protect seagrass, coral and wrecks (Posidonia in the Balearics, the Rhone wreck in the BVI, Hol Chan in Belize), and scuba in some parks is only allowed with an approved dive centre. By NOAA's 1991–2020 averages the sea stays at 24 °C or more all year in the BVI, Thailand, French Polynesia and Belize, while Mediterranean destinations range from 13.3 °C in late winter to 27.3 °C in August at our reference points, so by our rule of thumb a 3 mm suit or less is enough there only from about July to September (October in Turkey, August alone in Italy).
Where is the sea warm enough to snorkel all year?
By NOAA's 1991–2020 averages at our reference points, the sea stays at 24 °C or more all year in BVI, Thailand, French Polynesia, Belize. In the Mediterranean it reaches that mark only in summer.
Can I anchor anywhere to snorkel?
No. In the Balearics anchoring on Posidonia seagrass is banned (Decree 25/2018); the BVI ban anchoring in the Wreck of the Rhone park; Hol Chan in Belize requires its mooring buoys; Kornati allows anchoring only in listed coves. Check the destination page for your area.