[2] The regiment was a composite of three different types of battalions[3] and a headquarters and service company: 18th Marines was activated on 8 September 1942 and participated in actions at Tarawa, Saipan and Tinian.

[4] On Tinian there were two small beaches on the North end where an assault landing could be made with low coral ledges.

[5] The rest of the island had coral cliffs up to 15 feet in height at the waters edge negating any assault plans.

Commodore Paul J. Halloran (CEC) CB theater commander provided drawings of a conceptual landing ramp for the 18th and 121st CBs to fabricate.

[5] They mounted steel beams salvaged from Saipan's abandoned sugar mill on LVT-2s to create a portable assault ramps.