Rhinomarine: multihull hydrostatics

[Epoxus]

Hi guys,

I'm trying to get GZ righting arm curves from Rhinomarine for a multihull vessel. For simplicity I have just drawn 2 rectangular closed volumes and subsequently meshed these.

No when I compute the hydrostatics for heel angles 0,10,20,30,40,50,60,70,80,90 it fails with the error:

'Failed to compute rollover hydrostatics. Check you surface normal directions and make sure that all 'open' surface edges do not become submerged during heeled hydrostatics...'

If I decrease the heeling angles (<15 degrees in my case) to the point where one of the decks is not yet submerged it does run the calculation. However I would like to have the curve to at least the point of vanishing stability. I did check the normal surface directions and these are all ok. Also the hulls are fully closed. Does anyone have a suggestion on how to solve this? Thanks.