Cigar Reef is one of the stranger sites in the marinelife.org.au Rottnest guide: a reef that rises to about 15 m from a 26 m sandy bottom and is described as a good place to find odd creatures. The guide also warns that it is an area of odd currents with variable visibility, cold currents even in summer and strange thermoclines. Those conditions probably explain both the unusual life and the site's low profile - it is not a charter site and very little else has been written about it.

The mixing of water masses around the north-west of Rottnest, where the warm Leeuwin Current meets cooler inshore and upwelled water, can bring species that are not seen on the sheltered reefs, and the sand around the base is worth searching for rays, flathead and other bottom dwellers. The reef itself supports the usual limestone-reef fish and sponges.

The guide lists the same GPS coordinates as North Point Hole, which is probably a transcription error, so the position here is left blank; confirm it with local divers before planning. The site suits experienced divers with their own boat who enjoy exploratory diving and can cope with thermoclines and changing current. Carry a thicker suit or hood than the surface temperature suggests, and plan conservatively for 26 m on air.

For most visitors it is a curiosity rather than a destination, but for macro enthusiasts willing to put in the effort, the unusual finds are the attraction. A torch is useful even in daylight.

Private boat from Fremantle, Woodman Point or Hillarys along the north coast to the North Point area (about 25 km, 60-70 minutes). Marinelife.org.au gives the same coordinates as North Point Hole, so the exact position needs confirming with local divers and a sounder. Rottnest lies about 18 km west of Fremantle; allow 45-90 minutes each way by charter or trailer boat depending on the site.

Follow Rottnest Island Authority mooring and anchoring rules - do not anchor on reef or in sanctuary zones - carry a marine radio and log a trip plan, as the crossing of Gage Roads can turn rough when the afternoon sea breeze arrives.

An area of odd currents, variable visibility, cold currents even in summer and strange thermoclines (marinelife.org.au). Exposed to westerly and north-westerly swell; dive only on calm days, and carry extra thermal protection. General pattern at Rottnest: summer brings calm morning easterlies followed by a strong south-westerly sea breeze from late morning, so dive early; winter brings north-westerly fronts and large swell, with clear, calm spells between them.

Check the Bureau of Meteorology coastal forecast for swell height and period before committing.

Descend onto the reef top at about 15 m, circuit the reef down to the sand at 26 m looking for unusual species, and ascend on a DSMB, allowing for variable current. Agree a turn pressure before descending (half gas, or a third where current is likely), carry a DSMB, and make a 3-minute safety stop at 5 m.

No regular operator - private boats and dive clubs (e.g. UWA Underwater Club) only. Nearest dive services: Perth Scuba, Bucket List Diver and Dolphin Scuba (Perth/Fremantle) run Rottnest boat trips; there are no dive shops or air fills on the island.