The search for the five missing fishermen off the West Cork coast has been suspended for the evening and will resume again at first light tomorrow morning.
Navy and garda divers have spent the day diving at the site of the Tit Bonhomme.
Weather conditions at the mouth of the harbour improved overnight with light westerly winds allowing divers safe access to the site this morning.
Shortly before high tide, navy and garda divers anchored off Adam's Rock and began diving in and around the vessel.
The initial dive lasted about 50 minutes after which the navy divers came ashore and the garda team remained anchored at the scene.
The divers accessed some areas, but it is not known if they managed to get deeply inside the vessel.
Meanwhile, a remotely operated vehicle (ROV) has been brought to the quay side at Union Hall.
It can be used in areas that are difficult or dangerous for the divers to access and it is likely to be used at the wreck site tomorrow.
Gerard O'Flynn of the Irish Coastguard stressed it would be wrong to attach too much hope to the dive.
"There are strong indications, that all the crew were on deck, and as one man was rescued and another was spotted by search teams on Sunday, it is important not to place too much hope on the dive", he said.
He also stressed that the dive is only one aspect of a search that continues to include air searches and shoreline searches in and around the harbour.
The Tit Bonhomme sank in heavy seas off the Cork coast early on Sunday morning and five fishermen remain missing.
The missing men are skipper Michael Hayes, 52, student Kevin Kershaw, 21, and Egyptians Wael Mohammed, Saied Ali Eldin and Attia Shaban.