Many thanks for your reply and we don’t have a water tank in the bow so might be able to mount slightly further forward. With that in mind as I understand the top of the bow thruster tunnel must half the diameter of the bow thruster below the water line thus determining it’s minimum disteance from the bow. Have been looking and different manufacturers have different specs on force, ie. Vetus offer a 56KGf with a 150mm tunnel which is close to your 60KGF you mention. If we go for a 60KGF plus the tunnel size increases to 177mm which means further aft.
I look forward to receiving your update and if I find any more information I’ll post.
Once again Thank You.