HSI or SNI? bigmike April 15, 2018 Uncategorized The regatta formerly known as the High School Invite (HSI) Regatta, is now the South Niagara Invite (SNI) Regatta! ..and it is still on! May 19 -20, 2018. It is now posted on Regatta Central Registration deadline is May 13 at 11:59 PM.