Interestingly this is a similar search area to a few years back when Abby Sunderland needed rescuing Australia sent a Qantas A330 Airbus.
Later picked up by a fishing vessel. Tony Bullimore was picked up by an Australian Navy ship. You need some pretty decent sea-going vessels to look at a resuce in this area not to mention as a platform for searching for a CVR.
Solo sailor Abby Sunderland alive, awaiting rescue by boat | News.com.au