In his second letter on March 28th of the following year, from Archangel, Russia, Walton describes himself as lonely. He worries that his refined upbringing has made him too sensitive for the "brutality" of life at sea.
Walton's experience of loneliness as a terrible experience establishes the idea of the horror of isolation that is so important throughout he rest of Frankenstein.
Walton writes that his resolution to carry out his journey is "fixed as fate." He confesses his "romantic ... love for the marvellous" and his passion for the dangers of the sea, which he attributes to his fondness for Coleridge's poem, "The Rime of the Ancient Mariner."
Note the influence of Romanticism (and poets like Coleridge) on Shelley's work. Yet the fact that his view of the sea is based on books, not experience, establishes his innocence (and ignorance).