Marsh Shoal is a lightly documented reef off Coffs Harbour that Jetty Dive Centre lists among its occasional local sites, likely named after a local identity or feature in the same tradition as several other Coffs-area reefs (Black Rock, Bullocky Reef) whose names reflect local rather than official marine-park nomenclature. Depths run a moderate 12-25 m, putting it within reach of both confident Open Water divers and Advanced divers depending on which part of the shoal is dived. As with the other lesser-known local reefs in this area, marine life is typified by resident reef fish, occasional rays cruising the sand around the structure, and nudibranchs and other invertebrates in the reef's crevices, without the singular drawcards — grey nurse sharks, giant coral gardens — that define the marquee Solitary Islands sites.

Its value lies mainly in providing another workable option for the operator on days when weather or diver preference calls for a shorter, closer-in trip rather than the full run out to the islands. Because Marsh Shoal is not a headline attraction, exact GPS coordinates, precise depth range and a detailed species list are not readily available in published sources, and the description here should be treated as indicative of the general character of Coffs Harbour's local reef grounds rather than a verified site report. Divers interested in this specific site should ask Jetty Dive Centre directly about its current use and condition, and should not expect the same density of grey nurse sharks or coral cover that draws most visitors to the marine park's better-known island moorings.

Jetty Dive Centre departs from the public floating pontoon wharf in Coffs Harbour boat harbour, opposite the Attitude Burgers building (check in at 398 Harbour Drive). Private boats use the public ramp inside the harbour breakwall. These local reefs are all within a short run of the harbour and are used as backup sites when weather rules out a trip to the islands proper.

Conditions off Coffs Harbour depend heavily on which island is being run: North West Solitary and Split Solitary sit closer inshore and are usable in more marginal weather, while South Solitary and any northern sites need a bigger settled window. Visibility across the group is generally 8-25 m and best away from river influence; the Coffs, Bellinger, Nambucca and Clarence systems all periodically dirty inshore water for a few days after heavy rain. Summer (Nov-Apr) is warmest with tropical vagrants and mantas; winter (May-Oct) is cooler with grey nurse sharks and giant cuttlefish.

Humpback whales pass April-November. These inshore reefs are the fallback when even Split Solitary Island is unworkable, so they are typically dived only a handful of times a year.

Descend onto the shoal, explore the reef structure for rays and reef fish, and ascend along the same line to control the drift.

Jetty Dive Centre uses these reefs as close-in backup sites on days too rough to reach the Solitary Islands.