Not sure you got that one right Bazzman.

 

There are a bunch of different measurements used. Typically:

- LOA = Length over all - tip of bowsprit to end of swimstep/outboard pod etc

- LWL = Length at water line usually the length of the hull measured at the water line

- Length on Hull - depends you you are talking to a little what this means

- Bouyant Length - Usually LWL, but can be confused by transom extensions etc

- LOD = Length on deck

.... etc

You actually need different measurements to work out different things about your boat. If you want to know what size berth, drystack, or garage etc then LOA is important. If you want to know how roomy the boat is then LOD might be better than the next indicator of LWL or LOH.

 

Most manufacturers use the longest length to make their boat look better value for money. Some have a history of using 'hull length' and have stuck with it, whilst some other manufacturers have 'transitioned' there model sizes and what was once a 720 is now a 750 etc.

 

Some people will argue that the 'true' measurement is LWL or 'hull length', but when you compare a fine entry hull with a hull with a much fuller entry, LWL will tend to understate the room and 'seaworthiness'  in the fine entry hull. Whilst LOA might slightly underrepresent the fuller hull in the same comparison. I once had a '5.8m' boat that had a huge cockpit and room to sleep in the cabin fully stretched out. Reality it was a fuller entry hull and over 6.2m LOA. Much more boat than most 5.8's that you would buy today.

 

Bottom line is that the comparisons are not that simple, so when comparing models you need to look a bit further than the model number. Personally I prefer the LOA measurement as it is one that I can best make sense of. LWL or 'hull length' numbers leave more uncertainty in my mind, but I know many others who don't share that opinion..