Which Engine Oil Do You Use (& Why)

[Wotname]

What engine oil (mineral, semi- synthetic, full synthetic) and API rating do you use (for small yacht diesel engine like Yanmar, Volvo, Bukh etc)?

In another thread Dockhead posted this link Oil for yacht engines
and it got me thinking (usually not a good thing ).

A couple years back when I fitted a new 2GM20 I couldn't find the Yanmar recommended API CD rated oil in the local retail outlets so I did what the salesman suggested and used a CH-4 product.

The above link re-awakened my original concerns and I finally tracked down an Australian supplier of a API CD rated mineral oil - it wasn't easy
Most manufacturers no longer make oils to an obsolete rating.

So now I'm wondering what the rest of you use...