Big Brother - Numidia

The dive

This is not a separate reef. The Numidia is a wreck dive on Big Brother itself — she lies on the island's northern point, a couple of hundred metres from the position we hold for the island as a whole, and the two records describe one place. Treat this entry as the wreck and the Big Brother entry as the island and its walls.

The Numidia was a 130 m British cargo steamer that struck the reef in 1901 on a voyage from England to India. She sits on the steep northern slope with her bow wedged high — around 8 m, shallow enough that the shallows still hold two locomotive wheels from her cargo, which is why she is sometimes called the Railway Wreck. From there the hull runs down the slope: main structure from roughly 20 m, the mast reaching about 45 m, and the stern and propeller reported at 80 to 90 m. Only the upper part of that is a recreational dive; the rest is technical ground.

She is completely coral-covered after more than a century, which is much of the appeal — this is a reef dive that happens to be shaped like a ship. The other wreck on the island, the Aida (1957, 75 m), lies off the same end. The catch on both is current: it can be severe here, and the north point is where the flow splits. The occurrence record for this position is a rich reef list — coral grouper, cornetfish, Napoleon wrasse, black-and-white snapper, bluefin trevally, barracuda, anthias — with oceanic whitetip appearing directly in it as well.

• 130 m steamer lost in 1901, standing bow-up on Big Brother's north point
• Bow at about 8 m; hull runs down past 45 m to a stern reported at 80-90 m
• Locomotive wheels from her cargo still in the shallows — hence 'the Railway Wreck'
• Over a century of coral growth over the entire structure, with oceanic whitetips in the blue alongside

Conditions

A steeply sloping wreck dive in current on an exposed open-ocean point. Recreational profiles cover the bow and upper hull from about 8 m down to 40 m; below that the wreck continues into technical depths. Visibility quoted at 20-30 m and above (we record 20 m), water 23-30 C with reported thermoclines, and current that can be severe.

On current: Current on this wreck is specifically described as capable of being severe, on an island where current is strong as a rule and runs north to south along the walls — and the wreck sits on the north point, where the flow divides. Sources disagree on the wreck's own depths: bow at 8 m in both, but main structure 'from around 20 m' in one and the mast at 45 m in another, with the stern at 80 m or 90 m depending on who is writing. We record a recreational band of 8-40 m and treat everything below that as technical. Visibility is quoted at 20-30 m and above; we record 20 m.

Dives & underwater footage