There is a compromise involved i.e. how heavy an anchor is needed to stop a 19 ton boat plus the weight of the chain and rope attached to said anchor, against the lifting capabilities of the weakest crew member, me!
So the conversation in the chandlers went like this.
'How much does your boat weigh'
'How much can you lift?'
'I can lift almost 30 kilos'
'No you can't, that's much to heavy for you'
'Yes I can, I can lift 2 paper boxes at a time and they weigh between 13 & 15 kilos each'
'No you can't, try to lift this anchor, it's 9 kilos'
I picked up 2 at once, conversation over!