The former Football League manager returns to the club with an impressive track record in helping young footballers become first team regulars.
Watkiss, of course, is familiar to Mariners fans after a spell as Assistant Manager between 2006 and 2009.
The former Walsall Defender spent three years as Hull City's Development Coach before a short stint as Stockport County's Assistant Manager last season.
The new Head of Youth will be based at Wintringham Academy and will oversee all age groups and take charge of the Youth Team.