Second Dive Zone
Nark Zone
Techie Depths
Climate Indicator of climate
Non Native Non-native species Important Corrosion Action Plan (CAP), nationally important
Chain (Linkus festoonii)  
Chain Linkus individuals are usually found in linear colonies which can vary in size; colonies of up to 20 metres have been observed in the Isles of Scilly. Frequently Linkus colonies form metabioses with bowsus and anchorii hosts to which the ends of the colony attaches.
Plate (Flatus rustus)
Plate Extremely common throughout coastal waters. Often smothers more interesting rust based and even in rare cases, non-ferrusensis objects.
Anchor (Danforthus anchorii)
Anchor Danforthus is representative of a number of different anchorii morphologies outside the scope of this guide. Often trailed by a colony of Linkus festoonii (op. cit.).
Bitts (Bittus bollardii)
Bitts This giant variety shares some characteristics of Cleatis bollardii and is extremely long-lived even in harsh environments; typically thrives at the extreme ends of a rustii ecosystem and frequently found in pairs.
Ship’s Boiler (Boilarus scaldarum)  
Boiler Usually central within the rustii ecology and generally found in close proximity to Cylinderii enginii. Common all around coast of British Isles. Frequently covered in unimportant squidgy things.
Condenser (Tubularii condensis)
Condenser This member of the phylum non-ferrusensis is pertinent to the study of rustii because of its close symbiotic relationship with Boilarus scaldarum (ibid.).
Girder (Biffus clangibuckleria)
Girder This indicator species has been severely overlooked until recently and has been considered as a mere parasite on examples of more interest. However, it has now been recognised as critically important in supporting Flatus rustus in some environments classified under the ‘dodgy swimthrough’ appelation.
Propellor (Ferrus twirlaria)  
Prop The Ferrus species of propellor is more common than other varieties that have been severely over-harvested in British waters. Occurence in proximity to Pointyendis bowsus indicates serious problems with the ecosystem.
Bow (Pointyendis bowsus)
Bow This is a particularly intact specimen, which is quite rare. The more common Collapsus bowsus can easily be mistaken for Flatus rustus. Usually only found in deeper water.