... ??? I don't understand this at all.
You're a Plebe now, C/O 2027. So then you are referring to this upcoming Summer Cruise which is your 3/C Midshipmen (Indoctrination) Professional Training of Midshipmen (PROTRAMID). If you're a rising 3/C going to PROTRAMID this summer, then there's no way you will be in MAGTF... missing out on subs, surface, and pilot.
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I'm reading now the USNAINST 1530.1G (20 Mar 2023) - USNA Midshipmen Summer Training Program.
Paragraph 7.b.(1)(a). 3/C Midshipmen (Indoctrination). Approximately one week is spent with each community: aviation, surface warfare, submarine, Marine Corps.
Paragraph 7.b.(1)(c). 1/C Midshipmen (Immersion). Midshipmen desiring to be assigned as a Marine must attend Leatherneck or, under extenuating circumstances, MAGTF training. Note. MAGTF will only be considered a cruise when there is a shortage of of traditional options. This determination will be made by the Deputy Commandant for Professional Development.