6” x ¼”                               159lbs
152.4mm x 6.35mm             72.12kg 

I find this quite fascinating, and I'm afraid my comment here will be of absolutely no help to you in your project, but, here's the thing.

Somehow, I always expect aluminium masts to be lighter than other options, but I built my masts from essentially solid spruce and glassed them in epoxy and biaxial cloth, then painted with epoxy primer and 2 component polyurethane paint. Both of my masts are longer than the specs quoted here and they both have a max dia of 220mm, tapering to 100mm (approx). Now, I didn't weigh them, but my son and I could carry them relatively comfortably over a reasonable distance, so I estimate their weight to not be so very different (around 80kgs each mast) to those mentioned here.

Well, I find it interesting, anyway :)

I'm getting closer to making the final decision on my aluminum mast. I own a 24' Bayliner Buccaneer and want to run these numbers through to someone that knows more than I do. These are the sizes available locally, at this point, I'm leaning to the 5.5" Outside diameter with a 3/16" wall. That would be: 139.7mm with a 4.7mm wall.

All sizes are 6061-T6 Round tubing at 30 feet long. (9.144m)
Outside diameter X wall diameter with weight of each

5” x  3/16”                         100lbs
(127mm x 4.7mm               45.35kg)

5” x ¼”                               131.7lbs
127mm x 6.35mm                64.27kg)

5.5” x 3/16”                         74.4lbs
139.7mm x 4.7mm               33.74kg

5.5” x ¼”                             145.5lbs
139.7mm x 6.35mm              65.77kg

6” x 3/16”                            120lbs
152.4mm x 4.7mm               54.43kg

6” x ¼”                               159lbs
152.4mm x 6.35mm             72.12kg 

This is the sketch Arne drew for my boat, thank you for your guidance and suggestions