How does C. S. Forester use imagery in Mr. Midshipman Hornblower?

Example of Imagery:

"A January gale was roaring up the Channel, blustering loudly, and bearing on its bosom rain squalls whose big drops rattled loudly on the tarpaulin clothing of those among the officers and men whose duties kept them on deck. So hard and so long had the gale blown that even in the sheltered waters of Spithead the battleship moved uneasily at her anchors, itching a little in the choppy seas, and snubbing herself against the tautened cables with unexpected jerks. A shore boat was on its way out to her, propelled by oars in the hands of two sturdy women; it danced madly on the steep little waves, now and then putting its nose into one and sending a sheet of spray flying aft. The oarswoman in the bow knew her business, and with rapid glances over her shoulder not only kept the boat on its course but turned the bows into the worst of the waves to keep from capsizing. It slowly drew up along the starboard side of the Justinian, and as it approached the main chains the midshipman of the watch hailed it." (p. 3)