For in one hour - In a very brief period - so short, that it seemed to them to be but one hour. In the prediction Revelation 18:8, it is said that it would be "in one day" (see the notes on that place); here it is said that, to the on-lookers, it seemed to be but an hour. There is no inconsistency, therefore, between the two statements.
So great riches is come to nought - All the accumulated wealth of so great and rich a city. This should have been united with Revelation 18:16, as it is a part of the lamentation of the merchants, and as the lamentation of the mariners commences in the other part of the verse. It is so divided in the Greek Testaments.
And every ship-master - This introduces the lamentation of the mariners, who would, of course, be deeply interested in the destruction of a city with which they had been accustomed to trade, and by carrying merchandise to which they had been enriched. The word "ship-master" - κυβερνήτης kubernētēs - means, properly, a "governor"; then a governor of a ship - the "steersman" or "pilot," Acts 27:11.
And all the company in ships - Prof. Stuart renders this "coasters." There is here, however, an important difference in the reading of the text. The commonly received text is, πᾶς ἐπὶ τῶν πλοίων ὁ ὅμιλος pas epi tōn ploiōn ho homilos - "the whole company in ships," as in our common version; the reading which is now commonly adopted, and which is found in Griesbach, Hahn, and Tittmann, is ὁ ἐπὶ τόπον πλέων ho epi topon pleōn - "he who sails to a place"; that is, he who sails from one place to another along the coast, or who does not venture out far to sea; and thus the phrase would denote a secondary class of sea-captains or officers - those less venturesome, or experienced, or bold than others. There can be little doubt that this is the correct reading (compare Wetatein, in loco); and hence the class of seamen here referred to is "coasters." Such seamen would naturally be employed where there was a great and luxurious maritime city, and would have a deep interest in its fall.
And sailors - Common seamen.
And as many as trade by sea - In any kind of craft, whether employed in a near or a remote trade.
Stood afar off - notes on Revelation 18:10.

Every shipmaster - Captains of vessels; some think pilots are meant, and this is most likely to be the meaning of the original word κυβερνητης. This description appears to be at least partly taken from Ezekiel 27:26-28.
And all the company in ships - Και πας επι των πλοιων ὁ ὁμιλος· The crowd or passengers aboard. But the best MSS, and versions have και πας ὁ επι τοπον πλεων, those who sail from place to place, or such as stop at particular places on the coast, without performing the whole voyage. This sufficiently marks the traffic on the coast of the Mediterranean Sea. Some might debark (in sailing from Rome) at the island of Sicily, others at different ports in Greece; some at Corinth, others at Crete, or the various islands of the Aegean Sea; some at Rhodes, Pamphylia, etc., etc.; as in those times in which the compass was unknown, every voyage was performed coastwise, always keeping, if possible, within sight of the land.

(11) For in one hour so great riches is come to nought. And every shipmaster, and all the company in ships, and sailors, and as many as trade by sea, stood afar off,
(11) The manner of mourning used by them that trade by sea.

For in one hour so great riches is come to nought,.... That is, in a very short time, expressing the suddenness and speediness of Rome's destruction, the quick dispatch and expedition that will be made in it, by the instruments of it, as in Revelation 18:10. Rome was always famous for its great wealth and riches; the Jews have a saying (l), that if ten kabs of riches descend into the world, the ancient Romans take nine of them, and the other the whole world:
and every shipmaster, and all the company in ships, and sailors, and as many as trade by sea, stood afar off; the lamentation of the kings and merchants of the earth being ended, masters of ships, sailors, and seafaring men begin theirs: by "ships" are meant dioceses, abbeys, priories, and monasteries; and by the masters, or governors of them, bishops, abbots, priors, the heads of monasteries, and of the several orders of the Franciscans, Dominicans, &c. and by "all the company in ships", or "every shipmate", the fellows that belong to every religious house and order; and by "sailors" and "traders at sea", all such who compass sea and land to make proselytes to the Romish religion, like the Pharisees of old, and who, as they, make them two fold more the children of hell than themselves; and, in general, these traders abroad may design the pope's legates, sent by him into various parts, to collect his revenues, and the Jesuits, who are everywhere sent abroad to sow sedition and false doctrine, and the priests that travel about to sell pardons and indulgences: these
stood afar off; as the kings and merchants before, for fear of sharing in the condemnation and punishment of Babylon; knowing full well that they deserved it, having been associates with her in her crimes.
(l) T. Bab. Kiddushin, fol. 49. 2.

is come to naught--Greek, "is desolated."
shipmaster--Greek, "steersman," or "pilot."
all the company in ships--A, C, Vulgate, and Syriac read, "Every one who saileth to a place" (B has ". . . to the place"), every voyager. Vessels were freighted with pilgrims to various shrines, so that in one month (A.D. 1300) two hundred thousand pilgrims were counted in Rome [D'AAUBIGNE, Histoire de la Reformation]: a source of gain, not only to the Papal see, but to shipmasters, merchants, pilots, &c. These latter, however, are not restricted to those literally "shipmasters," &c., but mainly refer, in the mystical sense, to all who share in the spiritual traffic of apostate Christendom.