Marcoux, of Lexington, Mass., put together rounds of 71, 69 and 68 for a 5-under 208. He finished two shots off the winner.
The junior used three birdies, one eagle and a double bogey to move up the leaderboard in the final round and secure second place.
BGGA’s Tianyu “Jeffrey” Wu and Thomas Pfoestl also competed in the event. Wu, a junior from China, finished T25 with rounds of 71, 73 and 73 for a 4-over 217.
Pfoestl, a senior from Italy, finished T27 at 5-over 218 after rounds of 71, 70 and 77.
BGGA students will use this week to prepare to play in the IJGT Lowcountry Championship at Dolphin Head Golf Club in Hilton Head Island, S.C.