Ask where the last British passenger ship on a year-round scheduled service survives and people even in shipping circles would be hard put to find a reply. The answer, surprisingly, is in the Arabian Gulf. The ship is the Dwarka; for 32 years she has been sailing one of the oldest and most romantic shipping routes in the world. The Dwarka is a last survivor, an Imperial echo of the great network of routes established throughout the East in the days of the British Raj. Today, on the southbound voyage, she carries 1,000 passengers - all hoping to find their fortunes in the oil-rich Arabian Gulf.