"Magellan ordered Gaspar de Quesada to be decapitated and quartered." (421) This quote shows he does not have concerns for his crew because he had killed a member of his to crew to show and example to the rest of them.
In Document D it states "We ate old biscuits reduced to powder, rats, grubs, and we drank yellow stinking water" (425) This shows that they were determined to stay alive on there task and had to finish there end goal instead of turning back.
In Document C it states "Magellan even relied on the taste of the sea." (423) This helps us as readers to understand that he had good navigation skills .