How should you ring the Chief of Staff of CTF-70 when they come on board?

When the Chief of Staff of CTF-70 comes on board, the correct protocol is to ring the bell and announce "Staff" Arriving. This follows established naval traditions for welcoming distinguished visitors. The announcement identifies the onboard event clearly to all personnel, indicating that a senior staff member is arriving, which necessitates attention and readiness from the crew.

Using the term "Staff" is appropriate because it encapsulates a category of personnel that the Chief of Staff represents. This practice is important for maintaining the decorum and respect due to high-ranking officials, ensuring that all crew members recognize the significance of the visitor's arrival.

Other options may not reflect the correct formality or specificity required in naval announcements, thus emphasizing why the chosen answer is best in this context.