Fortress and naval harbour form the 1600's 60 berths. Good emergency harbour during a fresh gale, but not form the south. Visiting boats may seing anchor to the north of the swing bridge across the harbour. Large boats should moor along the quay on the east side. The hrbour should be entered with care day and night, allowances being made for wind, current and visibility. Compass variation can occur and strong current coupled with bad visibility can be cangerous. If a black ball or three vertical red lights are displayed/shinning on a mast on the south side of Frederiksoe Island, it means that the harbour cannot be entered due to rough seas or because all berths are occupied. The harbour entrance is too narrow for sailing manoeuvres. Speed limit: 3 knots. Anchoring prohibited.