Hi Claude, there is no real answer to that one. Are you fishing in the harbour or outside the harbour?  In shallow water you wont need anything too heavy. A selection of 1 to 12oz covers most situations

Hi, I will be going outside the harbour to deeper waters. Thanks

I just saw this. If anchored you need to hold the bottom. I'd go 4oz minimum, 8oz is better. Gets down fast.  You can use 100g jigs as well if drifting or the current isn't too much. 

I was just not willing to haul up the anchor 50m or so.

 I had to do it a couple trips back.. a poor contact inside the capatain pressure switch..
In not fit , no nor a big guy.. hover around 77kg...9m of chain, 3mX  8mm 6m X 6mm 4.5kg danford.
helm moved to boat up the current so could take the slack out easy..
 Bit more pressure as the anchor shaft turned over the blades and rolled free.. Bot moves back in current so take that slack up and anchor off the bottom.
 Straight 55m up.
 To be honest thought would take far more effort but no.. actually comes up slightly faster than with the capstan.
The 'hard part' was  thinking " when will this end, with a pictre in my mind dragging the anchor down our old 50mm drive way thinking about maybe where it is.. to fill in the time pulling up
 To be honest was rather disappointed in the lack of actual effort required.
 My old man in the 50s 60s , had tape on thru the  warp threads every fathom.. can count off and reduce the bordum pulling up maybe?