Ives had the satisfaction of seeing the Explorer, under the bright moonlight, slowly back out of the pit which had been her cradle into the swirling, seething current.  As the tide continued to rise, Ives feared the whole flat would soon be inundated, so everything belonging to the expedition was stowed on board till the Explorer’s gunwales were no more than six inches above the surface.  Through this circumstance, the expedition came near a disastrous end the next night, when the steamer proceeded up the river on the flood tide.  A squall was met and the boat shipped water alarmingly, but fortunately the wind died away as quickly as it had come up.  The Explorer was saved, and the journey was continued over the swiftly gliding torrent.

As they went on after this in daylight, some Cocopas they met grinned rather contemptuously, and called this the “chiquito steamboat.”  A considerable amount of stores was left on the bank in their care, to be picked up by Captain Wilcox, who, going down on one of the fort steamers, had passed the Explorer, and offered to take these extra stores to the fort on his return.  They were placed with the Cocopas by his direction, an arrangement that better describes the relations of the steamboat people and the natives than anything that could be said about them.  The fuel used was wood, of which there was great abundance along the shore, the hard, fine-grained mesquite making a particularly hot fire.  The routine of advance was to place a man with a sounding-pole at the bow, while Robinson, the pilot, had his post on the deck of the cabin, but the sounding was more for record purposes than to assist Robinson, who was usually able to predict exactly when the water would shoal or deepen.  Later, Ives says:  “If the ascent of the river is accomplished, it will be due to his skill and good management.”  Besides the ordinary shifting of the sands by the restless, current, there was another factor occasionally to guard against.  This was earthquakes.  Sometimes they might change the depth of water on the lower river in the twinkling of an eye.  On one occasion, a schooner lying in a deep part was found suddenly aground in three feet of water, with no other warning than a rumble and a shock.  Heintzelman, in one of his reconnoissances, discovered the adjacent land full of cracks, through which oozed streams of sulphurous water, mud, and sand, and Diaz, in 1540, came to banks of “hot ashes” which it was impossible to cross, the whole ground trembling beneath his feet.  At low water, even in the lower reaches of the river, a boat is liable to run aground often, and has to be backed off to try her fortune in another place.  The bottom, however, is soft, the current strong, so no harm is done and the rush of water helps to cut the boat loose.  One does not easily comprehend how sensitive a pilot becomes to every tremor of the hull in this sort of navigation.  The quality of the boat’s vibration speaks to his nerves in a distinct language, and the suck of the wheel emphasises the communication.