IALA buoyage · Safe water

Safe-water mark

Identical in A and B

Red-and-white vertical stripes with a single red sphere topmark: navigable water all around — the mid-channel or landfall mark.

LFl 10sOne long flash (at least 2 s) every 10 s.

One long flash (at least 2 s) every 10 s.

Pillar buoy; vertical stripes: red and white; topmark: one red sphere. Light: LFl 10s.

What it means
There is navigable water all around this mark. It marks fairways, channel centrelines and landfalls — it is not a danger mark. The only striped mark with a red sphere topmark. Identical in both IALA regions.
What you do
You may pass on either side. In a fairway, standard practice is to keep it to port so you stay on the starboard side of the channel.
Memory aid
Red-and-white candy stripes = all clear. Its white light is gentle, never quick: Iso, Oc, one long flash every 10 s, or Morse “A” (short–long, “Alfa — I’m arriving”).

Source: IALA Maritime Buoyage System — USCG Navigation Center, U.S. Aids to Navigation System