In the modern globalised world, the majority of goods carried by sea are shipped in leviathans plying regular routes from ports scattered across the globe. The relentless year-round progress of this long-distance ‘conveyor belt’, however, is far removed from the everyday life experienced by ancient mariners. At the mercy of the winds and of the seasons, in the Mediterranean much of the sailing would have been undertaken during a relatively restricted sailing season – or was it? In this thought provoking volume B. effectively argues that for the Graeco-Roman period in certain locations, seafaring could have been a year-round occupation.

This volume, which is based upon B.'s doctoral thesis, is a clear, well-argued and supported challenge to the literary-based orthodoxy that saw a maritime calendar in operation where seafaring was restricted to a six to eight month period centred upon the summer months. In Chapter 1, B. suggests that we are, in fact, misled by a selective reading of the texts and an over-reliance upon the calendars set out in Hesiod's Works and Days and Vegetius' Epitoma rei militaris, alongside an edict of the emperor Gratian that survives in the Codex Theodosianus, works which although separated by over a millennium propose dates that start and finish within virtually a month of each other.

The volume effectively challenges the idea of an open and closed season for sailing in the Mediterranean and presents a more nuanced perspective of winter, where voyaging may have been curtailed but certainly did not cease. B. effectively presents a maritime world in which taking to the seas in wintertime was not a rush into death driven by avarice (Pliny, HN 2.47.125) – a passage in Pliny that reveals more about the landlubberly attitudes of the Roman elite than of a seasoned sailor – but an everyday occurrence for mariners.

The use of modern weather statistics (Chapter 2) demonstrates the lack of climatic unity across the Mediterranean and B. argues that it is not, and in antiquity probably never was, the single entity that it is commonly regarded as. Such climatic diversity would have resulted in distinct, regional sailing conditions, with the result that in certain parts of the Mediterranean, such as along its eastern fringes, seafaring may have continued largely untroubled throughout the year, whereas in other places – the Gulf of Lions, for example – the stormy and unpredictable conditions in the winter months may have curtailed it. Such a view has much to recommend it, fitting as it does into the idea of Mediterranean micro-regions and regional connections of Horden and Purcell's The Corrupting Sea. Indeed, B. could have been more ambitious and linked this idea of the timings of regional weather patterns in to a more complex picture that explored the environmental motives that drove mariners to put to sea at certain times of the year. Did, for example, seafarers need to put to sea in wintertime in order to arrive at their destination ports at an appropriate time? Here B.'s discussion of the Elephantine customs register (pp. 17–21) is particularly useful, as it illustrates that for an Ionian ship to depart from a port in Egypt in March, it would have needed to have left its home port in February. Such an early departure from Greece was likely to have been driven by the receding flood waters of the river Nile, which would have made entry into Egypt for deeply drafted merchant ships difficult – if not impossible – during the summer months when the river was at its shallowest. Consequently, if merchants entered the Delta on its western side via its Canopic channel, and wanted to avoid the potentially costly and time consuming transhipment of their goods at Thonis-Heracleion and sail directly to markets in Naucratis or Memphis, they needed to enter the river and leave it at a time before its waters dropped and left them stranded high and dry. For such a voyage, winter sailing was a necessity not an option.

In considering the capability of fishing boats, pirate (Chapter 6) and military vessels (Chapter 1), B. opens out the discussion of seasonality. This is extremely useful, providing the important insight that not every vessel was as adept at wintertime voyaging as a sturdy cargo ship. Galleys, so prominent in the literary record and the inspiration for Vegetius' calendar, are particularly ill-suited to operating in large waves with their oar-ports set close to the waterline with the accompanying dangers of being swamped. Here the juxtaposition of the discussion of a lessening in pirate activity in wintertime due to their preference for galleys and the continuation of fishing is particularly useful. The wintertime arrival of large shoals of pelagic fish in the Aegean, for example, would certainly have encouraged fishermen to put to sea and take advantage of the seasonal abundance of this important source of food for both subsistence and commercial reasons. B.'s consideration of fishermen is interesting because it moves the narrative away from the types of vessels – particularly those discussed in conjunction with long-distance trade or warfare – that dominate the literary record and into the realm of everyday local and regional seafaring. For perhaps the majority of coastal communities short distance voyaging – moving goods around the local maritime ‘small-world’ and fishing in offshore waters – would have been the norm. For such communities it is likely that the seas would never have been closed to any great extent.

In moving the discussion away from the waters of the Mediterranean to those of the Indian Ocean in Chapter 5, B. outlines a compelling argument that suggests that as vessels built in a Roman style (discussed extensively in Chapters 3 and 4) could survive the harsh conditions of the monsoon winds, they could also survive the comparatively more benign waters of the Mediterranean in wintertime. While an entirely appropriate deduction, this line of argument is largely built upon the ancient literary sources that make it clear that Graeco-Roman ships were involved in this trade route, coupled with some ethnographic studies of Arab dhows that suggest that they were little more than fair weather craft (cf. pp. 225–6). This should be treated with some caution, however, as the comparatively recent discovery of the wreck of the ninth-century a.d. Belitung ship would suggest that an Arab dhow whose planks were sewn together with coconut fibre, rather than fastened using the mortise and tenon technique of the Graeco-Romans, could operate effectively in the Indian Ocean and sail to China. This opens up the intriguing possibility that if sewn vessels could survive in the Indian Ocean, perhaps the earlier sewn ships of the Egyptians and Greeks could also have sailed in the wintertime Mediterranean? This in turn opens at least the possibility of a much deeper (pre)history of sailing in the Mediterranean beyond the open and closed seasons.

The great joy and the importance of this volume is that it brings nuance and subtlety to a question that might, at first, seem straightforward: Graeco-Roman mariners either sailed during the winter months or they did not. Instead we are presented with a Mediterranean full of regional patterns where seafarers weighed up the risks and adapted their sailing strategies, including whether to sail over open water or hug the coast, depending upon the season. This is not to say that maritime traffic in the winter was on the same scale as in the summer, and here B. cogently points to the litigations in the Demosthenic corpus of the fourth century b.c., where contractual obligations strongly encouraged voyages to be completed by the middle of September and penalised late returns (Demosthenes 35.10). Rather than unthinking obedience to a set timetable, we are presented with knowledgeable and purposive sailors and investors who weighed up the necessity of the voyage and the potential profit and risks before embarking upon storm-tossed seas.