Can a helmet be worn with the roof on?

[Walton]

Hi

I'm thinking of getting a older Caterham for some cheap sideways winter trackday fun.

Is it possible to stay dry in the rain on track i.e. wear a helmet with the roof on?
Alternatively are most leather cockpits waterproof?

Thanks

Rich

[Walton]

Thanks

By old I mean just 5yrs old or so.

I'm about 5'11.

I've done enough wet trackdays, but can't remember how the Caterhams run ie. with or without roofs.