seaweed as fertilizer

I am having difficulty getting hold of farmyard manure so I was thinking that as I live half a mile from the seaside that a smal trailer behind the car could cart me all the manure/fertilizer that I need for free .

Should I compost it first.Should I soak it with fresh water to get rid of the salt or would it be better just to put it on the soil in the autumn as you would with manure.

Any tips would be greatfully recieved

I use it a lot, both in the compost bins and as a liquid feed. I've had a load stewing since last back end and it should give me around 6 gallons of feed which I dilute before applying. The right combination of winds and tides has recently pushed up great piles of material onto the foreshore. This consists of a mixture of grass, leaves and seaweed and odd bits of plastic. Over the last few days I've collected 11 sacks of it which will be composted for use next year. As BiB says, it has lots of trace elements in it that are lacking in farmyard manure.