You'll need to set attribution. The IMC process sets the ocean data to:
Layer 80
Lower Limit 0
Upper Limit 34
Fill Color 16
Border Color 9
MajCat "Nautical"
MinCat "Ocean/Sea"
You'll probably want to use the extents option (Advanced Options->Extent Options), as well, so you aren't generating an ocean polygon for the entire world...just your area of interest.