36 foot boat, 3.5 tonnes, anchor type TBA.

Intention is to typically anchor in 4-5 meters.

Seems like this would be ideal - any issues with this? I wasn't sure about the breaking load - 750KG seems like not a lot for a marine application!

www.bunnings.com.au/pinnacle-8mm-5-16-x-12m-stainless-steel-chain_p0358141

For a 36 footer I would use 12m of 10mm stainless. Check what your winch needs if fitted.

For me the first step was to find a quality supplier that backed their product. Mine is 39ft and 11ton fully loaded. Ended up getting 80 metres 8mm which has been used a few times in deep anchorage and / or heavy weather. Only downside is the weight in the bow drops the bow waterline a little unless in cruising mode and weight is stored aft. There's a great supplier in Kirrawee NSW that'll give a good price if you pick it up.