Using ancient documents, artifacts, and archaeological excavation on land and under water, Casson’s work presents a broad but coherent story of trade and warfare from 3000 BC to 1000 AD, from rowboats to freighters, from Spain to Malay.  Although Casson moves through 4000 years of technological and political development without overt links to his own time (1960s Britain), there are perhaps four key "lessons" for an attentive reader:  1) risk and long distance trade have been around for as long as recorded history, as has been 2) the arms race, which was once a naval arms race, so 3) woe betide the country or empire that gives up a position of strength on the seas, and 4) efficiency in port taxation and excellence in naval recruit training are synonymous with national success.

Sea Empires
The earliest drawings and models of ships are found in late fourth millennium BC in Egypt and Mesopotamia. Egypt's power to control shipping lanes and resist attacks by pirates waxed and waned with the interest and ability of its Pharaohs.  By the time of Tutmoses the III (c. 1570 BC) the Minoans were becoming a force to be reckoned with, and Crete's influence is found in dress and pottery styles copied across the Mediterranean.  By 1450 BC the Minoans gave way to the rising power of the Myceneans on the Greek mainland until the end of the Bronze Age.  (Incidentally Casson reads the Argonautica as a trip to the Black Sea in the Homeric Dark Ages of 1200 BC, and remarks that it is the first story about a voyage that is undertaken on hearsay, for the sake of adventure as much as wealth.)  Phoenicians (red-cloth men) dominated trade in 1000 BC, the Biblical time of the Judges (Iron-working as well as trading was a Phoenician skill).  Following the Phoenicians were the Greeks (again) as they sent out colonies and contended with the Persians until 300 BC, when the Romans began to build a navy to fight Carthage.  Despite the general landlubberly ineptitude Casson insists upon, they were so successful that the Mediterranean became a Roman lake until 400 AD, after which Byzantium, the Arab kingdoms and the Venetians were each in turn powers in the area.

Key Innovations in Marine Technology
Essentially ships can be put together in one of two ways:  by first creating a planking hull, and then adding an internal frame to stiffen and support the hull, or by first building an internal frame, and then adding a hull to the frame.  The Portuguese and Spanish ships of the 1400s were built the latter way, but most ancient ships were built the former way.  In particular, underwater wrecks show that ships were often constructed with carpentry worthy of the New Yankee workshop:  mortise and tenon joints placed close together run down the length of each plank.

Early boat design -- or what we can see of Egyptian boat design from tomb walls -- was, naturally, for river use, not seafaring.  Boats were constructed without a center keel or mast; rather, a webbing underneath the prow and stern, planking woven together, and a hawser attached at either end and twisted and tightened in the center of the boat to stiffen the frame, were common features.  Longer distances required sturdier designs, and soon keeled ships with sunk masts topped by square sails were put to use; in fact, variations on the Greek penteconter was the "ship of the line" for almost 1,000 years.  Vases, tombs and monuments provide the visual evidence of ship design and development.  Casson traces the naval arms race through various sea empires from Greek triremes up to the gigantic Roman "forties" which he believes were double-hulled catamaran style ships.   Three levels of rowers were used, but each oar was manned by several recruits (eight men were the maximum). He argues that slaves were never used to any extent in any empire's navy; they were simply too expensive to be expendable.  Key developments in naval development were in casting of large bronze rams for Greek triremes, boarding devices like the "raven" (corvus) and the catapult grappling tackle that allowed the Romans to use ships as devices for carrying marines rather than weapons in and of themselves, and very late (or very early) Byzantine flame throwers.  Perhaps more interesting was the device that allowed the Romans to win the Mediterranean for themselves.  In 67 BC, the Cilician pirates bit the hands that fed them one too many times, and Pompey was commissioned to solve the problem once and for all.  He divided the entire Mediterranean into 13 sectors, and sweeping west from Gibraltar, cleaned up, in four months, a problem that had been intractable for 2000 years.  Not new weapons but a vision of the Mediterranean as a whole, with sufficient ships and organization to cover that whole, became a key naval technology.

Important Trade Routes, Ports, and  Business Practices
Early trade flowed from Egypt and Mesopotamia through Byblos, on the Palestinian coast.  By 2000 BC Mesopotamian clay tablets give the details of raising capital and hedging financial risk for traders traveling as far as Bahrain. Egypt likewise records trading missions in preserved papyrus and in tomb and temple walls. From Old Kingdom to New, Lebanese cedar trade and African spice trade was carried on. (9) Casson argues that several ancient captain-adventurers got fairly far down the African coast, and out through Gibraltar up to England and Denmark, but perhaps some of the more well-known trade routes of ancient times were 1) the Greek grain routes through the Dardanelles up to the Black Sea; 2) the Roman grain routes from Alexandria to Rome; and 3) the relatively ancient luxury trade routes to the Indian Ocean.  Winds are all-important; on the Alexandria-Rome grain route traders had a quick two week trip down to Alexandria, but a one-month trip back, tacking against the wind and skirting island coasts all the way.  Summer winds favored traders traveling down the Red Sea to the Indian Ocean, and reversed agreeably for the winter trip back.  Pepper, frankincense, ivory, pearls from Africa, Arabia and India, as well as silks from China, were luxury goods, but copper from Spain, pottery from France and glassware from Asia Minor were also part of the luxury trade.  Cheap wine, grain and oil were staples (except Egypt, where the Ptolomies taxed wine so that the locals would stick with beer). Besides grain, oil, wine and fish paste (garum), slaves taken on raids were one of the most common "commodities." By contrast to warships, merchantmen were often entirely captained and crewed by slaves (blue-collar and white-collar work alike was done by slaves). For the duration of the time covered by Casson, pirates and storms were the two most significant risks for traders.  Traders very often worked in partnerships to fund a trip, and returns on a luxury 6-month to one-year trip (the typical duration) were high if they were successful at all.  Would-be trading or political empires had to construct ports, and Casson describes in some detail the facilities at Athens, Delos, Alexandria, Rhodes and Rome.  (It is clear he favors Rhodes as being the most "British" of them all.)  On a final note, the size of shipping vessels increased until 1800 foot-long boats with a draft of 44 feet and a beam of 45 feet, holding 1200 to 1300 tons of grain, were built. More than 600 passengers were with Josephus when he traveled to Rome by grain ship in 64 AD.