Final answer:
The phrase 'have been swept out to sea' is an incomplete sentence indicating that something or someone was carried away by the sea, likely due to a storm, and lacks a subject. It is used within a narrative to convey the struggle and peril faced by characters at sea.
Step-by-step explanation:
The analysis of the statement 'have been swept out to sea' suggests that it reflects an action where something or someone was carried away by the sea, indicating a forceful removal due to natural elements, such as a storm or waves. This phrase does not form a complete sentence; it lacks a subject and is therefore an incomplete sentence. The context provided from various excerpts indicates a disastrous sea voyage, where the ship and its crew encounter perilous situations, leading to the reasonable inference that the ship, with the initials L.S., was indeed destroyed by the storm, as per Dr. Watson's implication.
The usage of 'have been swept out to sea' within the narrative presents a vivid imagery of the struggle against nature's indifference and the frailty of human endeavors when confronted with the overwhelming power of the sea. The excerpts from 'The Open Boat' show characters overcoming challenges and facing the brink of survival amidst the tumultuous ocean.