Relitto Bolzaneto

The dive

The Bolzaneto was a transport steamer launched in 1918, 86.96 m long, 12.50 m in the beam, 2,220 gross tons and good for 8.5 knots. She survived an air attack in the port of Genoa almost unscathed, then was torpedoed off Bonassola in Liguria in June 1943 while carrying a cargo of iron ingots and cast iron, which was later salvaged. The torpedo struck her amidships and she broke cleanly into two pieces and went down fast. Sources do not agree on the date: relittiliguria.it gives 9 June 1943 at 10:45 and names the British submarine Sportsman, while Scubaportal gives 29 June 1943. On the casualties, the Diving Group Portofino record ten crew and the captain lost; Scubaportal say nearly the whole crew died.

The wreck lies on a sandy bottom in two pieces about 150 m apart. The bow was almost entirely destroyed by the explosion. The stern is the dive: it rises out of the sand with the propeller and a good part of the hull showing at around 45 m, and the aft 105 mm gun is still sitting in its firing position, which is the image everyone comes away with. Ammunition for the gun is still in the holds, and the operator's description adds the rudder blade, the steering chains, the funnel and small holds leading toward the engine room and galley. Most of the wreck is draped in nets and fishing line.

Depths quoted are 40 to 56 m, with the operator giving a 51 m average, and the minimum gas requirement everyone states is normoxic trimix -- 21/35 or 18/45 in the operator's version, 20/30 with nitrox 50 for the decompression in relittiliguria.it's, which caps bottom time at 20 to 30 minutes at 55 m. Conditions are the honest problem here rather than the depth. Scubaportal describe the wreck as almost always surrounded by poor visibility and say currents are not rare; the operator is more generous, calling visibility moderate and current weak to moderate. Plan for the pessimistic version.

There is a lot of life on her for a wreck this deep and this dark: clouds of anthias, moray and conger, spiny lobster and European lobster, nudibranchs and porter crabs, with jewel anemones growing on the cannon itself and shoals of horse mackerel and anchovy drawing in amberjack and bonito. Spiny lobster, noble pen shell and Noah's ark shell are all recorded in the occurrence data around this pin. Eleven men died here, and under Italian heritage law anything of cultural interest lifted from the seabed belongs to the State, so the shells in the holds stay where they are.

• The 105 mm stern gun still in firing position
• The propeller and rudder blade clear of the sand at about 45 m
• The stern section standing proud while the bow is wreckage
• Jewel anemones growing on the cannon
• Clouds of anthias, with moray, conger and lobster through the structure

Conditions

A boat dive offshore of Bonassola onto sand. The stern section is the target and gives you a shape to descend onto at about 45 m; beyond that the bottom is at 56 m. Sources describe the water around the wreck as usually murky and the current as present often enough to plan for. The operator runs it with a minimum group of six divers at 95 EUR a dive excluding gas fills.

On current: Depths given as 40 to 55 m (relittiliguria.it), 40 to 56 m with a 51 m average (Diving Group Portofino) and a 56 m bottom with the stern showing at about 45 m (Scubaportal); plan on 56. Visibility is where the sources part company: Scubaportal say poor visibility almost always surrounds the wreck and currents are not rare, while the operator calls visibility moderate and current weak to moderate. Take the conservative reading.