Flying Bass Straight isnt that daunting, last weekend i crossed it twice, albeit in a Cessna 206 at 180Kts GS. from our cruise height of 4500ft, we could see an island of some sort at all times. and once on Flinders Island, its only a very short over water section to mainland tassie. to be honest, i am more concerned flying over tiger country west of Sydney and the snowy mountain regions.
when crossing the straight, its all about preparation, especially the survival gear IF something should go wrong. water ditchings are quite survivable, and statistic show most are, but the waters of the straights are very cold.
Also, dont forget about the overwater scheduled radio reporting. every 15 mins. though, at C206 ground speeds, we only ever made the initial report, and within the 15 mins we were over flinders Island.
Via King Island, the longest overwater leg was from King Island to Victoria, about 60nm.