HO is 1:87 and OO which is as close as you get in Ireland and in the UK is 1:78, I think. For American HO, I have also used ship models that are 1:96, which is a more standard ship scale and I've even used the 1:28 scale models of the Blue Devil Fletcher class WWII destroyer and 1:128 scale Seaview from Voyage to the Bottom of the Sea.