Metaphor

When slave ships embarked on the Middle Passage throughout the centuries-long period of the transatlantic trade of enslaved people, they often carried an object called a speculum oris. A speculum oris is a metallic device that was originally ‘designed by surgeons to deal with lock- jaw’ (Walvin Reference Walvin2011: 36–37). Slave ships, however, carried a speculum oris for a different reason, for the refusal of food was a widespread strategy of resisting the horrors of enslavement. Indeed, this form of resistance was so important that historian Marcus Rediker (Reference Rediker2007) argues we may think of the transatlantic trade of enslaved people as a four-hundred-years hunger strike. The speculum oris, thus, was taken onboard in anticipation of respective strikes and used to ‘force-feed resistant Africans’ (Walvin Reference Walvin2011: 37).

While particularly horrific, the speculum oris was not the only means by which the anticipation of resistance was built into ship design. To prevent people from jumping overboard, that is, choosing death by drowning over the enslavement in the plantations, nets were installed around the vessel or people chained to the deck (Rediker Reference Rediker2007; Walvin Reference Walvin2011). Moreover, to anticipate rebellions, ships were specifically built:

What the built-in anticipation of resistance on slave ships tells us, then, is that ships can be both: an essential technology of colonial capitalism and a site of resistance (Linebaugh and Rediker Reference Linebaugh and Rediker2013; Scharenberg, Reference Scharenberg2025, Vessels of Solidarity). Thus, for the decolonial scholar Malcolm Ferdinand, slave ships are ‘a political metaphor for the world’, because they hold the capacity ‘to concentrate the world within them’:

Crucially, for Ferdinand, the metaphor of the slave ship does not only help us better understand the horrors of the transatlantic trade of enslaved people – it may also help us move beyond what he calls modernity’s double fracture and think together both colonial and environmental injustices. Ferdinand, in a similar move to Mann’s ‘commonist lifeboat’, mobilises the ship as a metaphor to radically rethink politics in times of climate crisis in the shape of what he calls a ‘world-ship’.

As Mann demonstrates in an earlier article (Reference Mann2024), the use of ship metaphors is not new. Indeed, ships and lifeboats have been mobilised as metaphors throughout the history of political theory and philosophy. Mann himself cites one of the most famous examples: Plato’s ship of state simile, in which the ship works both as a metaphor of good and bad governance. For Plato, ‘a ship with an orderly crew and a competent steersman’ represents ‘his ideal city’, while ‘a ship with an unruly crew’ stands for ‘the Greek cities with which he was familiar and of Athens in particular’ (Keyt Reference Keyt and Santas2006: 189). Foucault’s often-cited idea of a ship as a ‘heterotopia par excellence’ (Reference Foucault1986: 27) similarly captures this Janus-faced meaning of seagoing vessels, in which the vessel represents both the status quo and its radically different alternative. For Foucault, a ship is a heterotopia in the sense that it functions both as an ‘instrument of economic development’ as well as being ‘the greatest reserve of the imagination’: ‘without boats, dreams dry up […] and the police take the place of pirates’ (27).

Like in these famous examples of ships in political theory and philosophy Mann’s contrasting analysis of the lifeboat metaphor as either ‘providential’, ‘catastrophic’ or ‘commonist’ reveals both the problems of the status quo and how we might move beyond it. As such, Mann’s lifeboat can, first of all, be read as part of a wider history of employing ships as political metaphors. At the same time, what makes Mann’s discussion of ships particularly compelling is that, for him, ‘these lifeboats are not only metaphors’ (Reference Mann2025: 2, original emphasis). Rather, Mann’s – as well as Ferdinand’s and Rediker’s – use of the ship metaphor is ‘historically grounded’ (Mann Reference Mann2025: 1). In his case, the metaphor of the ‘commonist lifeboat’ is, amongst other aspects, ‘rooted in the historical realities of maritime custom’ (22).

Custom

When the Russian anarchist Pyotr Kropotkin wrote about mutual aid, he was inspired by a distinctly maritime iteration of the practice, namely the mutual agreement to provide support to people who find themselves in distress at sea:Footnote ¹

The UK’s Royal National Lifeboat Institution (RNLI), originally called the National Institution for the Preservation from Shipwreck, which Kropotkin sees as a prime example of mutual aid, is but the institutionalised form of a custom that is much older than the organisation’s inauguration in 1824. As Mann writes, the practice of rescuing people in distress at sea has existed for centuries. It is with reference to this ‘larger normative universe that constituted the life of seafarers’ that Mann develops his political theory of the ‘commonist lifeboat’ and within which, he argues, ‘the duty of rescue and survival cannibalism’ need to be understood (Reference Mann2025: 4). His theory of the ‘commonist lifeboat’ derives from a combination of the two, demonstrating that survival cannibalism onboard the Mignionette only makes sense in the wider context of the custom of rescue at sea, that is with the prospect of being rescued on the horizon.

I agree with Mann that a customs-focused analysis can give way to new political theories and practices. Elsewhere, Peter Rees and I show this by theorising the role of the sea in civil sea rescue to advance our understanding of solidarity with maritime migrants, based on ethnographic work conducted with civil society groups operating in the English Channel and the Mediterranean Sea (Scharenberg and Rees, Reference Scharenberg and Rees2024). Here, we show how reference to maritime customs was used to challenge illegal pushback practices developed in conjunction with the UK’s Secretary of State for the Home Department, in which UK Border Force vessels were supposed to be used to physically push small boats transiting the English Channel back into French Waters. One of the organisations we conducted research with legally challenged the practice in a claim that was based in maritime law and drew on the Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996 (COLREGS) and the expertise of master mariner Captain John Simpson. Here, attention to maritime custom strengthened their case, for Simpson concluded that ‘the pushback policy was “completely at odds with the ordinary practice of seamen, good seamanship and a contravention of the COLREGs” (emphasis added)’ (6).

Crucially, however, Rees and I stress that we also need to pay attention to the materiality of the sea itself, for it is the material specificity of the sea from which certain customs derive in the first place. Mann acknowledges this in From Survival Cannibalism to Climate Politics when he argues that it would be ‘impossible to understand the duty to rescue, without close attention to the role that weather played in nautical imagination’ (Reference Mann2025: 8). Indeed, the weather and ‘environmental characteristics of the sea’, which seafarers are equally exposed to in their ‘encounter between humans and nature’, are a ‘constitutive’ element for the custom of rescue to emerge (8, emphasis added). As Mann writes elsewhere: ‘What enabled rival power to come together and formulate rules for mutual assistance between their ships was a common external enemy – nature’ (Reference Mann2024: 94). Like in Kropotkin’s description of the ‘fearful snowstorm’, Mann pays attention to numerous environmental aspects throughout his article, including sailors’ ‘dialogue with water, moon, and marine life’ such as turtles and, possibly, sharks (Reference Mann2025: 7–8); the very ‘gale’ that shipwrecked the Mignionette out at sea in the first place (3); or the lack of drinking water that led them to first consume a turtle, and later one of their fellow travellers, in anticipation of rescue by another ship. Comparing seafaring customs like the duty to rescue to other contexts, Mann also shows how ‘in deserts too the natural threat has given birth to traditions of sharing, hospitality, and mutual assistance’ (18).

It is such ‘custom and local practices’ of mutual aid that Mann values in his conclusion, arguing that ‘careful consideration of custom can broaden our political horizon’ (22). At the same time, Mann cautions us that it is not advisable to blindly follow all historical traditions and customs merely because they have existed for a long time. Given this note of caution regarding the application of custom in his conclusion, as well as his references to environmental aspects throughout his article, I want to suggest a complimentary, materialist reading of the ‘commonist lifeboat’, which understands the lifeboat not primarily as a metaphor or a site of customs, but asks how the materiality of the sea and the ship itself may shape alternative practices and customs to come that can help us navigate through an era of climate change.

Materiality

When I boarded a civil sea rescue vessel in a Central Mediterranean shipyard in the spring of 2023 as part of my ethnographic fieldwork with ocean activists (Scharenberg Reference Scharenberg2024, Reference Scharenberg2025), one of the first observations that particularly struck me was how much the materiality of the sea and, indeed, the ship itself seemed to matter for how solidarity with maritime migrants was practiced. While it is the EU’s lethal migration policies that makes this kind of solidarity work necessary in the first place and which even actively limit solidarity actors’ capacity to perform rescues, as several scholars have demonstrated (see, for instance, Mainwaring and DeBono Reference Mainwaring and DeBono2021, Tazzioli, Reference Tazzioli2018), it was the materiality of the sea and its effects on the ship that shaped our daily routines in the shipyard:

Indeed, over the last decade, geographic scholarship of the ocean has already demonstrated why attention to the sea’s elemental qualities, including its wetness, movement and turbulence, matters for how we understand ocean politics and governance (for instance, Steinberg and Peter Reference Steinberg and Peters2015, Lehman et al. Reference Lehman, Steinberg and Johnson2021). What my brief anecdote from the shipyard demonstrates, then, is that the ship’s materiality, too, is worth considering in this context (Scharenberg Reference Scharenberg2024, Reference Scharenberg2025). Once again, besides discussing the marine environmental aspects of Regina vs. Dudley and Stephens, Mann also acknowledges the need to pay attention to the materiality of lifeboats elsewhere in his work. In a co-written article with Keady-Tabbal, the authors demonstrate how the materiality of the lifeboat gets weaponised as a tool of border violence in the context of Europe’s so-called ‘migration management’ in the Aegean, ‘transforming life-saving materials into life-threatening ones’ (Reference Keady-Tabbal and Mann2023: 62)

Crucially, however, attention to the materiality of ships can not only help us better understand the status quo of ocean politics but also lead to a new understanding of political theory and practice. What my discussion of the material politics of civil sea rescue ships revealed is that what emerges here is an alternative way of organising political community. Rather than being organised along the borders of nation states, this community is held together by what I call ‘vessels of solidarity’, which work according to a different spatial logic that connects solidarity actors ‘across categorical, spatial and temporal boundaries’ (Scharenberg, Reference Scharenberg2025, p. 8). Linked by the vessels’ material need for labour, resources and collaboration between different organisations as well as with solidarity cities and ports in which the ships receive further support and shelter, respective infrastructures of solidarity illustrate how political community may be organised beyond sedentary forms of kinship (see also Scharenberg and Rees, Reference Scharenberg and Rees2024).

The story of the speculum oris – the metal object used to force-feed enslaved people on hunger strike during the Middle Passage – which I mentioned earlier in this text, is another case in point of how alternative forms of kinship can come into being via the material conditions aboard ships. Rediker shows how the term ‘shipmate’ was used by people who had survived the horrors of the Middle Passage to refer to a kind of ‘seafaring kinship’ that derived from shared experiences of the daily torture but also acts of resistance onboard slave vessels (Reference Rediker2007: 306). The term kinship, here, is broadened ‘from immediate family…to the whole of the lower deck’: This kinship is based on having had the same food, having slept on the same planks, having ‘shared violence, terror, and difficult conditions, as well as resistance, community, and finally survival on the lower deck of the slave ship’, and forms what Rediker understands as ‘miniature mutual-aid societies’ (304–306). Kinship, in other words, is derived, quite literally, from having been in the same boat together. Here, more than a metaphor, the ship is a material site of radical political practice from which alternative conceptions of community might emerge.