True Honor by Dee Henderson

True Honor (Uncommon Heroes, Book 3) - Retired CIA agent Darcy St. James is called back to work because a Russian contact, Sergey, has requested a meet with her.  While she is waiting for contact Chief Petty Officer Sam "Cougar" Houston is taking a break from his partner, Tom's wedding.  They meet and talk until Darcy sees her contact.  Sam goes for a walk but runs to the pool when he hears a splash.  Darcy, who can't swim, is bleeding and struggling to get out of the pool.  Darcy was not the only agent targeted, others around the world have been killed.  Sam escorts her back to Langley.  Then September 11 happens.  While Darcy and her partner, Gabriel, work the intelligence, Sam and SEAL Team Nine travel the world taking out terrorists they uncover.