HMS Colossus


Heritage Category:
Maritime Wreck
List Entry Number:
Date first listed:
Date of most recent amendment:
Location Description:
Off Southward Well, Samson Island, Isles of Scilly


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The building or site itself may lie within the boundary of more than one authority.

Location Description:
Off Southward Well, Samson Island, Isles of Scilly
Marine Location Name:
National Grid Reference:


The site comprises the scattered remains of HMS Colossus; a British 74-gun Third Rate Ship of the Line bound from Naples to Portsmouth with Greek pottery for Sir William Hamilton, and wounded personnel following the Battle of the Nile, which struck Southward Well in a storm, broke up and sank in 1798. The Colossus was built in 1787 at Gravesend.

Reasons for Designation

HMS Colossus is designated under the Protection of Wrecks Act 1973 for the following principal reasons:

* Rarity: the 74-gun Third Rate ship of the line was a naval development wholly characteristic of the later C18 and the Colossus is the only designated example of a Third Rate of its generation;
* Potential: the vessel has considerable potential for providing insight into late C18 construction materials and techniques;
* Vulnerability: the wreck remains vulnerable to souvenir hunters and uncontrolled salvage;
* Documentation: the importance of this vessel is considerably enhanced by the information obtained from archaeological survey and surviving Admiralty records, and;
* Historic: the Colossus is associated both with significant naval actions and characters of the late C18, as well as with the age of the Grand Tour and the transport of antiquities to Britain.


HMS Colossus was a 74-gun third rate ship-of-the-line built at Gravesend, and launched in 1787. Its last naval engagement was at the Battle of Cape St Vincent (1797), during the course of which she was badly damaged. The Colossus was stripped of her stores to repair the serving ships, and ordered to return to England, carrying wounded from the battle, along with prize items and part of a collection of Greek antiquities amassed by Sir William Hamilton.

The Colossus approached the Channel in December 1798, and Captain Murray decided to take anchorage in St Mary's Road in the Isles of Scilly to await favourable winds. On the 10 December the main anchor cable parted in the gale, and the ship dragged her remaining anchors to come aground on Southward Well Rocks. The Colossus was subject to extensive salvage in the year following her wrecking, before she finally broke up.

The bow section of the Colossus was located in 1972 and the site was designated under the Protection of Wrecks Act in 1975. Investigation took place under licence funded by the British Museum. More than 30,000 shards of Greek pottery had been recovered by the time the site was de-designated in 1984. Most of this pottery is now in the British Museum where individual vases were painstakingly reconstructed, using detailed drawings of the vases prepared by artists before the collection left Italy.

Fifteen years later, part of the stern section of the Colossus was discovered. This includes a large section of ship structure, cannon, and among other items, muskets, mizzen chains, a rudder gudgeon, ropes and pulley sheaves. A carved figure from the port side of the stern of the vessel was also identified, excavated and recovered. This new site was designated in 2001 and the designated area includes a substantial 'debris' area of other material, such as shot, timbers, cannon and small artefacts.

The Colossus has been extensively researched and investigated in the last 20 years by the former Archaeological Diving Unit, Wessex Archaeology, the Cornwall and Isles of Scilly Maritime Archaeology Society (CISMAS) as well as several independent researchers. The site is also attractive to licensed visiting divers following installation of a diver trail guiding divers around the visible ship structure and armament. Most recently, investigations by CISMAS has developed a new understanding of the loss of the Colossus by correlating the archaeological and artefactual deposits with documentary evidence. This work has enhanced knowledge of the relationship between the bow and stern sites.


Designation History: Designation Order: No 773, 2017 Made: 18th July 2017 Laid before Parliament: 19th July 2017 Coming into force: 18th August 2017 Protected area: defined by the following co-ordinates:

N: 49.92688286, -6.34111824 E: 49.92371411, -6.33617442 S: 49.91861193, -6.34401542 W: 49.92178068, -6.34895924

No part of the restricted area lies above the high-water mark of ordinary spring tides.

Documentary History: HMS Colossus was a 74-gun warship built in 1787, and wrecked off Southward Well, Samson in the Isles of Scilly in 1798. The 74-gun ships were one of the most successful types of the period. They were typically about 51m (170 feet) in length and had a crew of approximately 600. During her relatively short career (11 years) she saw action at Toulon, Groix and Cape St Vincent.

In December 1798 the Colossus was on its way home to England with wounded from the Battle of the Nile and a cargo including Sir William Hamilton's collection of Greek pottery. She arrived off the Scilly Isles on 7th December and anchored off St. Mary's. During 10th December the wind steadily increased until it was blowing a full gale. Her topgallant-masts were struck and she rode safely until at 4 o'clock in the afternoon the anchor cable parted. The small bower anchor was let go and brought her up after she had drifted a little way. Captain Murray became worried at the position of the ship, and planned to set sail, but the pilot doubted if they could weather the rocks, so they prepared to ride out the storm. The sheet anchor was let go, topmasts struck, and yards trimmed, but it was soon found that she was dragging her anchors. At about 6 o'clock she struck the ground, although quite gently at first. Thoughts of lightening the ship had to be abandoned because of the shoal of water surrounding them, it being feared that if the guns were heaved overboard, the ship would strike the rocks. They hauled taut the anchor cable, which initially freed them, but dragging in the ebbing tide she struck the ground again, this time very hard. Pumps were manned, but the water gained, and by midnight the rudder had come away with the constant pounding on the ledge of rocks near the island of Samson, called the Southward Wells. By daybreak the water was up to the sills of the upper deck ports and the ship was beginning to break up. Local boats attended them to take off the crew, which was accomplished by 3pm that afternoon. All the crew were saved 'excepting one quarter-master, who fell overboard in heaving the lead.' Archaeological History: The forward part of the Colossus was originally designated under the Protection of Wrecks Act in 1975. Following recovery of a large number of pottery shards from Sir William Hamilton's collection and other artefacts, this designation was revoked in 1984.

In 2001, the current (stern) site was discovered some 350m to the east of the bow site. Considerable amounts of timber were exposed on the seabed along with a row of five iron guns, standing upright, their muzzles buried in the sand - still within their gunports. Most striking of all was a twice life-size carved wooden figure; part of the stern decoration of Colossus, lying face upwards on the sand. The former Archaeological Diving Unit (ADU) undertook an excavation in September 2001 to recover the stern decoration. This, however, proved to be too extensive to recover with the equipment available; it was therefore reburied for the winter. The area around the stern of the vessel was surveyed prior to the excavation by means of a photomosaic.

Following geophysical survey, the stern carving was excavated and eventually lifted in June 2002. The ADU carried out further geophysical survey in 2002, sponsored by the Time Team. Since 2003 sediment levels on the site have been monitored by the Cornwall and Isles of Scilly Maritime Archaeology Society (CISMAS) in conjunction with Historic England, and further material has been exposed, particularly in 2014-15.

The site is both fragile and vulnerable; the sediments that once covered the site appear to have moved and exposed all classes of organic material. The site lies in a depth of about 10 metres of seawater, with the seabed in the vicinity consisting of coarse, white, sand and fine crushed shell. Timber elements of the wreck are currently exposed on the seabed, and this exposure appears to be recent, due to ongoing sand erosion from the site.

The fabric of the vessel is remarkably well preserved; however, once it is exposed it is subject to fairly rapid deterioration due to biological decay. The timbers are exposed owing to erosion of the sand on the seabed. The deterioration of exposed timbers between discovery in June 2001 and final survey in June 2002 was marked, visibly gribbled and decayed. Once timbers are weakened by biological attack they will be subject to detachment and dispersal by the tide and wave surge during winter storms.

The rear half of the port side of the vessel lies flat, preserved in the sand. The wreck includes the six aftermost gun ports on the main gun deck, five of which still have 32-pounder guns pointing through them, with their breech ends uppermost. The ship's structure appears to be complete from the top of the gun ports on the upper gun deck to the turn of the bilge well below the waterline.

Today, the site consists of a bow site, debris trail and stern. The debris trail so far consists of timber, metalwork, lead scuppers, cannon balls, cannon and other small finds, such as pulley sheaves, copper nails, ropes, and buttons belonging to those on board. A large proportion of the port side stern is believed to survive on the seabed and there are various outlying artefacts. Framing and deck timbers, brass gunlocks, pulley block cheeks and sheaves, spoons, scissors, wine bottles, medical flasks, pottery shards and leather shoes have all been recovered from the site. Some of these items are now on display at the Isles of Scilly Museum.


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:
AMIE - Wrecks


Books and journals
Cornwall and Isles of Scilly Maritime Archaeology Society, , The search for Colossus: A story of wreck and discovery, (2006)
Morris, R., HMS Colossus: The Salvage of the Hamilton Treasures, (2006 - paperback edition)
HMS Colossus: Investigation 2015: Project Report, Kevin Camidge, 2015


This site is designated under the Protection of Wrecks Act 1973 as it is or may prove to be the site of a vessel lying wrecked on or in the sea bed and, on account of the historical, archaeological or artistic importance of the vessel, or of any objects contained or formerly contained in it which may be lying on the sea bed in or near the wreck, it ought to be protected from unauthorised interference. Protected wreck sites are designated by Statutory Instrument. The following information has been extracted from the relevant Statutory Instrument.

Statutory Instrument

Information provided under the Statutory Instrument heading below forms part of the official record of a protected wreck site. Information provided under other headings does not form part of the official record of the designation. It has been compiled by Historic England to aid understanding of the protected wreck site.

Statutory Instruments: 1975/726

End of official listing

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