The Rangers and USA captain sealed the move late in the transfer window and will switch to Spain's second tier.
He hopes his move from Scotland's fourth tier to Spain will help him to continue as an integral part of the USA's bid to reach the World Cup in Brazil in 2014.
Bocanegra will now look to help the Spanish port town team off the bottom of the table after they lost their first two matches of the season.
The 33-year-old has been an ever present for Ally McCoist's side this season with seven appearances in all competitions.
His experience saw him handed the captain's armband at the start of the campaign.
The American international made 34 appearances and scored three goals in his debut season in Glasgow last year.