Spanish government ships have entered British waters around Gibraltar more than 600 times since the start of 2013, the Foreign Office has said.
There were 496 unlawful incursions during 2013, with a further 112 in the first three months of 2014, it said.
Tensions between the UK and Spain over Gibraltar have not abated.
Foreign Secretary William Hague said the incidents were "unacceptable". He said that the UK would use "proportionate naval, police and diplomatic responses" to protect the area from further violations.
Since December 2011, Spain’s ambassador to the UK has been summoned to the Foreign Office over incidents and situations. The most recent time was earlier this month after a collision between a Spanish Guardia Civil vessel and a Royal Gibraltar Police vessel.
Any time a Spanish boat makes “unlawful maritime incursions into British Gibraltar territorial waters”, it is challenged by the Royal Navy, according to Mr Hague. There follows a formal diplomatic protest to the Spanish government.
"Our challenges and protests make clear that such incursions are an unacceptable violation of British sovereignty", he said.
Britain has controlled Gibraltar since it was handed over by the Spanish in 1713.
