To keep your head above water is a colorful expression that means staying out of debt.
VOA: special.2009.05.10
Essentially Citigroup is contesting a decision made by Mr Bondi to exclude it from the list of Parmalat's creditors, a step that would, if upheld, keep the bank outof a future debt-for-equity swap prior to Parmalat's re-flotation on the stockmarket.