What diameter do think the largest one's were?

I think the largest ones where around 2m (6-7ft), Evan. They are very impressive!

We have them at our Botanical Garden too; however, they have never reached quite that size.

I tried filling in some data on both amazonica and cruziana. V. amazonica was covered at MOBOT, cruziana is more elusive. Everything I read indicates cruziana is more cold hardy, being a sub-tropical native to Argentina and Paraguay, while amazonica, native to the Amazon basin, is a tropical. I you find any hardiness data on cruziana please propose it. Also MOBOT indicates amazonica is a perennial while other sites describe Victoria as an annual. Since they're mostly grown from seed I'm guessing they mean that's how they are treated.

One of the sources I found indicated that 55 gallon drums work well as a "pot" while a minimum 3'W x 2'D pot will work. The structure on the undersides of the leaves is really amazing. Check out google images.

The cruzianas are indeed more cold tolerant which is why we are able to grow them more successfully in Southwest Florida. The amazonicas can be overwintered but only with great effort since they decline fast under 50 degrees.

The structure of the underside of the leaves is indeed very beautiful and unique, and I can assure you - also very vicious, as our water-gardener will be able to tell you from experience.

So the cruzianas are perennial as well? There are modern chain mail shark suites made for divers. maybe your water-gardener should lobby for one.

Hetty, if you get a chance would you mind checking the data entries on these?

I will.

Thx.