THE government has conceded that the navy is under pressure, after a boat crowded with the largest number of asylum seekers to arrive in Australia in more than a decade landed this week.
A further two boats arrived at the tiny Indian Ocean territory of Cocos Island with a total of 55 people on the vessels last night.
Immigration Minister Chris Bowen said yesterday that rescuing asylum seekers was putting increasing operational pressure on the navy, when he was asked about reports that navy patrol boats were cracking under the strain of rescues.
''Of course, that's the case, but they'd also be doing other work as well,'' Mr Bowen said.
On Wednesday, navy patrol vessels went to the aid of a boat with 211 people aboard off Christmas Island.
A distress call from a passenger said the boat was low in the water.
It seems passengers and people smugglers have not been deterred by the death of about 90 people in June, when another crowded boat capsized.
More than 7300 asylum seekers have arrived by boat this year, compared to about 4500 people for the whole of 2011.
Coalition immigration spokesman Scott Morrison said the Coalition was incredibly concerned about the number of people getting into boats.
''The record level of arrivals to Australia is putting increasing strain on our border protection,'' he told reporters.
Mr Morrison said that government should reinstate the Coalition's border protection polices that include temporary protection visas, offshore processing on Nauru and turning boats around where it is ''safe to do so''.
''This government is in a deadlock of their own fabrication,'' he said, adding that it was only Prime Minister Julia Gillard's ''stubborn pride'' that prevented her from taking the Coalition's advice.
Home Affairs Minister Jason Clare said yesterday that the navy had found cracks in the engine room of the HMAS Armidale - which comes under the most pressure in rough weather - and minor cracks in two other patrol boats.