What is the fine-grained topic of the following text: The Navy Systems Commands (NAVSEA, NAVAIR, SPAWAR, NAVFAC, and NAVSUP), the Office of Naval Research, Military Sealift Command, and the United States Marine Corps compete their service requirements amongst 2400+ SeaPort-e IDIQ multiple award contract holders. Only return the topic.
Navy Systems Commands' service requirements competition among SeaPort-e IDIQ contract holders.