Following this thread with great interest. Thank you for all your comments. I'm finding them hugely inspiring - and reassuring!

Logistical issues at my end mean I'm struggling to get to see the Sarum 28 I linked to, but I'll keep you informed.

I'm also interested in the comments re. construction. As a new sailor, I'm thinking it would be better to have the extra safety margin of an aluminium boat for high latitude stuff for the times if/when I mess things up. Probably (almost certainly...) overkill I know but given there isn't too much of a cost penalty, I'm still thinking I should err on the side of caution.

Not only condensation on the inside, but also salt spray on the outside of fixed windows, however good the doghouse design. OK, in an extremely small ocean going boat, it might very occasionally be wise to seal yourself inside, barrel-fashion; but the Sarum 28 is not that small and vulnerable to knockdowns. Only when one has experienced having one's eyes, ears and nose outside gathering all available information, and one's body inside in relative shelter, does the genius of the Hasler pramhood become apparent.

Assuming that the layout includes a heads compartment to port, extending to the centreline as in the example that Hans-Erik found, then it would appear reasonable to offset the mast to port also, between the heads bulkhead and the forehatch, with a high AR rig. However, if it needs to go through the forehatch aperture, it should be straightforward to bolt a thick piece of aluminium plate in place of the forehatch, as a basis for the mast partners.

Hi, I have also found the Sarum 28 has caught my eye for more adventurous sailing as it is made of aluminium. Normally there are more for sale on the market, seems a bit quiet at the moment. Regarding the conversion to Junk rig, are you thinking the mast will go through the hul where the forward hatch is? have you investigated what work might need to be done for the structural integrity? also what an estimated budget might be for conversion?.  I think for higher latitude saling you might consider a doghouse.  I am interested to hear how you get on if you proceed, best of luck!

I don't disagree with David on this.
Here is an attempt with AR=2.25 and with SA around 40sqm (and the CE in the same position). It should still outperform the Bermudarig, and be very easy to handle.

But again, it depends on where you can step the mast.

Arne

Offset junk rig?  From personal experience, it is astonishing how few people even notice!  You see what you expect to see.

And, should the sale fall through, there is no necessity to have a metal boat for high latitude sailing.  Any well-found boat will be quite suitable, unless you choose to winter over, frozen in the ice.