Final answer:
Cassio and Othello are separated during their battles at sea due to various circumstances such as different locations and operations.
Step-by-step explanation:
Cassio and Othello are separated during their battles at sea due to various circumstances. In the case of Othello, he was engaged in war and was stationed in different locations, which resulted in him being separated from Cassio. Additionally, Cassio and Othello may have been involved in different operations or missions that required them to be deployed separately.