Lieutenant St. Vincent Halfhyde, beleaguered hero of this 1890s nautical series, left the Royal Navy to learn the merchant-marine trade in Halfhyde Outward Bound (1984)--and he's now ready to become owner/captain of his own commercial steamship, with financial help from a kind uncle. (A major motive: to stay as far away as possible from horrid, sexless wife Mildred, acquired via a virtual marriage-of-convenience.) So Halfhyde, in Australia, eagerly buys the Taronga Park from an aged captain--only to find a shortage of cargo opportunities in Sydney. Haplessly, then, he winds up agreeing to transport ""cased machine parts"" to Ireland for shady trader Porteous Higgins: the ""parts"" are really guns for Irish rebels, of course; and, once the Taronga Park sets off, Halfhyde discovers that much of his crew is secretly in the employ of vile Higgins--who is himself also aboard, accompanied by mute thug Gaboon and comely prostitute Victoria! A rough crossing ahead? Yes indeed. Halfhyde and Higgins battle for control of the ship, with several of Halfhyde's loyal men murdered. Near Chile, Halfhyde's brave First Mate goes purposely overboard--vainly hoping to reach land and get help from the British Embassy. Meanwhile, Victoria becomes Halfhyde's bedmate/ally; the ship has storm and engine trouble, requiring a tow. And when the Taronga Park does eventually reach its destination, the struggles for power shift to the bogs of Ireland--where Halfhyde is briefly taken hostage by the rebels, where villains Higgins and Gaboon get their just deserts from their supposed comrades-in-rebellion. Highly implausible but violently lively melodrama-at-sea: a sturdy series installment, without the sheer silliness that has marred previous entries--or the humor that has sometimes been a Halfhyde plus.