Some interesting replies.
The engine arangement means that the cooling does not go through the leg but has a seperate cooling intake. This means I could shut of the salt water intake and open a flushing point, closing both and trapping fresh water in the heat exchanger if required if benificial.
The enine is fresh water cooled (Yanmar 240hp), but was curious but unsure as I know that you need diferent anodes in fresh water and so it could have been worse in freshwater with the wrong anodes then in salt water with the right anodes.
This was also the reason for the outdrive question, I know the drives are well protected (Bravo 2) but would like to have as much out of the water as poss to prevent fouling BUT in rasing the leg and no dought lifting some of the anodes out of the water would the be sufficient anodes left in the water to do there job.
Anyway as Brian said the manufactures must give you this info, but would the engine manufacture(Yanmar) out drive manufacture(Mercruise) of the boat manufacture (Ribcraft).
Also on anodes was shocked the UK prices for anodes £65+VAT a set
Then when I looked at the states, got quoted $35. a set plus $30-$50 shipping.As i am told I may need 2 sets a year as the boat will be in the water all year I plan to order a few sets from the states, or does anyone know somwhere in the UK whos prices are realistic.
US Prices 5 sets $35*5 +$50 P&p =$225 (£145+ VAT approx)
UK Prices 5 sets £65 325+VAT
(me thinks were getting ripped off again
Anyway will find out when it gets delivered (I hope)