Hi Tommy, I can't answer you question directly but will make a couple of general points to try and help you:
1. Is SalviMar an American or Italian company ? Are the footpockets they sized in
US shoes sizes? If so, you will definitely need a larger numeric size than your UK size (I generally wear UK 11, EU 45 & US 12 - but footwear sizes vary
a lot).
2. If you buy them too small, you will need to: return them/sell them on/loose weight/stick them unused in a cupboard/wear them such that they restrict your circulation, making your feet cold/wear them without socks - actually ok in the warmer months, not so much in winter (but your feet shrink in winter, well mine do, so socks might fit then).
3. If you buy them
a little large you can always buy thicker neoprene socks to pad them out.
4. Shoes sizes in/on shoes/boxes/bags are notoriously unreliable/inaccurate. Shoe size conversion charts are even less reliable and less consistent (they are cr@p). Although not perfect, I find the EU sizes are generally the most consistent/reliable for most of my needs (i.e. 45).
Size conversion tables: google something like "UK USA shoes sizes" & select "Images" from the menu-bar
e.g. Notice that even these 2 charts are inconsistent (e.g. is UK 11 the same as USA 12 or USA 12.5? EU 45 or 45.5?). DO NOT RELY ON THESE CHARTS (or any other shoe size conversion chart).
