Crab,
On SAR S61's we routinely go below MSA using a combo of GPS (Rnav) and the weather radar which works really well for coastal mapping.
You can buy moving map now for about 1000 euro which are incredibly accurate and will give you all the SA you need 360 degrees. I know they can be integrated into the S92 displays or bolted onto the glareshield for us who still operate the old stuff.
Decks.