Porat (Biševo) Anchorage Guide

Anchoring Zones

Porat (Biševo) has 3 distinct anchoring zones, each with different depth, holding, and exposure characteristics. Choose the zone that matches your boat size and the expected overnight conditions.

Setting Your Anchor

The bottom at Porat (Biševo) is primarily sand with reliable holding when properly set.

1. Approach slowly and check your depth sounder. At 3–6m, deploy minimum 7:1 scope (42m chain at 6m depth).
2. Drop into the wind and pay out chain steadily as the boat drifts back.
3. Set firmly in reverse — 30–60 seconds at moderate throttle. The chain should tighten without the boat moving backwards.
4. Snorkel to verify bottom type. Posidonia is widespread around Vis — confirm your anchor is on sand, not Posidonia (anchoring on it carries fines up to €2,000). Use the scope calculator to confirm adequate chain.

Recommended anchor types: Rocna, Mantus, Spade. See our guide to anchor types by bottom.

Overnight Anchoring & Anchor Alarm

Overnight stays at Porat (Biševo) are feasible but require monitoring — the anchorage is exposed to W and SW and NW winds.

Set your GPS anchor alarm to 65m radius before going below. 65m for the main bay in 3–5m on sand with 5:1 scope. The bay faces W and is fully exposed to W, SW, and NW winds — overnight is suitable only in settled conditions with no W component forecast. Day use is fine in typical summer Mistral (NW) conditions as the swell is limited by the relatively short NW fetch from Vis island. Reduce to 45m in the sheltered N margin. In any W swell, this anchorage is untenable — return to Komiža.

Day use May–October. Overnight only in June and September when settled high-pressure conditions are most reliable and W swell least frequent. July–August day use is excellent but overnight is risky due to afternoon thunderstorm cells developing from the W. The Blue Cave tour boats run May–October subject to sea conditions. In winter, Biševo is accessible only by local fishing boat in settled weather.

Navigation Hazards

• W, SW, and NW exposed — any W swell makes the anchorage untenable immediately; return to Komiža if any W component forecast develops
• Extreme day-trip boat congestion 09:00–17:00 in season — speedboats and tour boats operate at speed in and around the bay; maintain anchor watch during these hours
• Blue Cave approach channel in the S bay — do not anchor in this area during tour boat operating hours
• Biševo is remote (9nm from Komiža): ensure engine reliability and sufficient fuel before making the passage, particularly in summer when N winds can make the return slower
• No facilities: carry all water and provisions from Komiža; the island cannot resupply you
• Night swell from W: even in calm daytime conditions, W swell can arrive at night from distant Atlantic depressions — monitor Sea State forecasts

Rules & Regulations

• eNautička (MMPI) permit: Required for all foreign yachts — carry aboard at all times.
• Anchoring fee: Free to anchor in the bay
• Maximum stay: 1 days
• Restrictions: Day use only recommended — W exposure makes overnight unsuitable except in perfectly settled weather. Do not anchor in the Blue Cave approach channel (S bay) during operating hours. Blue Cave access is via managed tour boats only — private dinghies and tenders may not enter without a tour operator guide.
• 150m beach exclusion (SSVO 2025): No anchoring within 150m of public beaches, June 15–Sep 15.

For a full overview, see our overnight anchoring rules by region guide.

Facilities

• Fresh water: Not available on site
• Fuel: Not available — nearest: Komiža (9nm)
• Restaurant: Small seasonal konoba in the hamlet of Porat — open intermittently when the family who runs it is resident; serves simple fish and local wine. Do not rely on this for provisions. Nearest full facilities at Komiža (9nm NE).
• Provisions: None on site — Komiža (9nm)

Skipper's Tips

1. The Blue Cave (Modra špilja) is best seen 10:00–12:00 when the sun angle maximises the underwater light refraction — book a Komiža tour boat timed for this window
2. Arrive at Porat before 09:00 to anchor before the day-trip fleet arrives — the morning bay is extraordinarily beautiful and completely peaceful
3. The evening after the day boats depart (17:00+) is the most magical time on Biševo — if the weather is settled, overnight is worthwhile for this experience alone
4. The small konoba in Porat village is a true time-capsule experience if you find it open — simplest food, local wine, hospitality from one of the last permanent island residents
5. A mask and snorkel in the bay entrance (not inside the cave) reveals the underwater cliff systems and exceptional clarity — visibility routinely exceeds 25m
6. Check the forecast for the following 36 hours before committing to overnight: you need to be able to return to Komiža in any conditions that develop