weight aloft

[mariner2k]

I've created a pattern for a bronze alloy mast cap for my new mast. But the guestamate on the weight was about 25-30 lbs. I made it a bit thick for overkill strength, but ultimately thought it necessary to reduce the thickness and weight, which I've done. I know that weight aloft effects the performance/ righting moment of the boat, but how much? I'm happy with the pattern now but I am still curious. The boat is 47' loa with a 55' mainmast.