Wright, 25, has drifted out of the first-team picture since first moving to Glanford Park in January 2008.
Despite that he has amassed 59 appearances in all competitions for the Iron, mostly in midfield but also as full-back.
He will go straight into the Mariners squad for the Blue Square Premier game against Wrexham on Tuesday night.
Wright was the second loan deal completed on Tuesday, with goalkeeper Richard O'Donnell extending his spell from Sheffield Wednesday by a month.