The anticipated exhaustion of the home grounds led to the steam trawler prospecting further afield. These longer voyages, as far as Iceland and the White Sea and Morocco, were very successful. The result of this was that larger steam trawlers were built, capable of undertaking long voyages of many weeks’ duration. Between 1900 and 1906 the average net tonnage of the steam trawlers increased from 54 to 62. The steam trawlers, in opening up new and more distant fishing grounds, left the home grounds to the smacks. Consequently we find that the smacks confined their operation to the smooth ground in home waters, leaving the rough and more distant grounds to the steam trawlers. A direct result of this gradual redistribution of the fisheries between sailing smacks and steamers was the development of specialized fishing ports. Such ports as Lowestoft, Brixham and Ramsgate, off which good fish are obtainable and which are within easy access of good markets, have retained their importance as smack ports; on the other hand, the development of steam trawling has led to the rapid growth of deep water ports, such as Fleetwood, Grimsby, Hull, Aberdeen, and Milford Haven. In Grimsby, originally one of the greatest strongholds of smack fishing, smacks have been entirely displaced by steam trawlers, owing to the special facilities which the port offers in being near cheap coal, in possessing deep water, and in being in direct rail communication with large markets for trawl fish. There is no doubt that the rapid development of steam trawling was accelerated by the invention of the otter trawl. This is not only a larger net than the beam trawl, but is for all but small, flat fish, a much more efficient instrument. From the study of market statistics between the years 1889 and 1898 Garstang has calculated that a steamer caught on the average between four and seven times as much fish in the year as a sailing smack. [Illustration: FIG. 16 I.—PLAN ON DECK. II.—PLAN BELOW DECK. _Plan of Arrangements on and below Deck._—(I) On deck: 1. Winch. 2. Hatches. 3. Gallows. 4. Bollards. 5. Fish-pounds. 6. Steam-winch (for trawl). 7. Blocks. 8. Officers’ messroom. 9. Galley. 10. Ventilators. 11. Funnel. 12. Bunker-hatches. 13. Engine-room skylight. 14. Bathroom. 15. Mate’s cabin. 16. Lifeboat. (II) Below deck: 1. Collision bulkhead. 2. Crew’s quarters. 3. Storeroom. 4. Iceroom. 5. Fish-hold. 6. Reserve coal bunker. 7. Main bunker. 8. Side bunkers. 9. Stokehold. 10. Main pump. 11. Auxiliary pump. 12. Engines. 13. Dynamo. 14. Cabin. 15 and 16. Chief and second engineers’ quarters.]