4oz weight adequate for the wear and as john says lads use a lot less when fishing the upper reaches,the tyne i would not use anything less than a 5 oz as the tide pull is a lot greater,probably pay to take an assortment of leads with you so you can change to adapt to the tide and weather conditions,if you need to put a bait out seventy eighty yards and the wind is in your face then a six/seven oz lead is going to help with the distance,just all depends on what rod your using