WWL-C vs WWL-1B

I am in need of a WA for my RX100V in a Nauticam housing. I have now a scratched UWL-04 that I got for free almost, but trying to buff out the deep nicks it had and polish it up was not that easy. It still has some haze and won’t become super clear again. 
 

So, I have been looking at the UWL-09 (acrylic) for some time, not wanting the big WWL-1. I have also lately become aware of the WWL-C which is quite a lot more compact than the WWL-1. 
 

I have not 100% made up my mind on glass/acrylic, but thinking I might as well go with glass. 
 

And now I see the WWL-1B is also available. Anyone has any experience with both the -C and the -1B? Pros/cons with them both? 
 

As I can find the -C can only be used on compacts, and the -1B can be used on compacts and bigger mirrorless housings. I would like the most compact one, but if the -1B allows a future upgrade and the -C don’t it might be worth going for the -1B? 
 

The WWL-C is optimized for a 24mm equivalent focal length to get 130 degree FOV. The WWL-1 &B are optimized foe a 28mm equivalent focal length for the 130 degree FOV. I use the WWL-C on an ASP Fuji with a 15-45mm Lens. The full zoom range is usable, except on the 15mm(23mm equivalent) there is slight vignetting .

1 hour ago, Raptor^ said:

As I can find the -C can only be used on compacts, and the -1B can be used on compacts and bigger mirrorless housings

That's not quite true, you just need the right lenses - WWL-C is made for 24mm-equivalent lenses, so you need a 24mm (or slightly wider, if it can zoom) lens with a small front element. Nauticam chart for WWL-C lists Nikon Z 24-50mm, Canon RF 24mm macro, Sony FE 24mm f/2.8 and Sigma 24mm f/3.5 - those are all full-frame cameras. You can also use it with APS-C with Sony E 16-50, Nikon Z 16-50mm, Fuji X 15-45mm and Canon EF-M 15-45mm, as well as micro four thirds with Panasonic 12-32mm.

I've seen claims that WWL-1 gives better image quality than WWL-C, but I have yet to find any head-to-head comparisons of something like Sony FE 24mm + WWL-C versus 28-60mm + WWL-1.

The difference between WWL-1 and WWL-1B is that the latter has an integrated metal float collar and only comes in Nauticam bayonet mount, while the latter has an optional foam collar and can be set up for 67mm threaded mount. WWL-C only uses the Nauticam bayonet, just like WWL-1B.

Ah ok, very useful answers that clears things up quite a bit, thank you. 
 

The RX100V at least is 24mm equivalent at the wide end, so that might favor the WWL-C for now as the -1B might vignette at the very wide end? And then if I upgrade to APS-C or FF, but most likely APS-C plan ahead a bit with what lenses to get. Although a fish eye, I like to get a view and results as close to the Tokina 10-17 as possible if I upgrade the compact 
 

Just need to think ahead then a bit to try and figure out which one will have most versatility and makes the most sense to buy. 

12 minutes ago, Raptor^ said:

The RX100V at least is 24mm equivalent at the wide end, so that might favor the WWL-C for now as the -1B might vignette at the very wide end?

It will, but you can get rid of that vignette with a touch of zoom. I use a UWL-09F with a Sony 16-50mm, and zooming in to 19mm (28mm-equivalent) gets rid of the black corners.

Here is the WWL-C port chart, quite a few lenses can be used with it. 

https://drive.google.com/file/d/1xvwt_9DKYlt8iOAIuNYeslhMA4bHuhqy/view

While you can zoom in to allow you to use the WWL-1B, it's another fiddly thing you need to do. 

I would strongly recommend you get the WWL-1 

I have had this lens forever and has served his purpose for

Sony RX100

Panasonic GH5

Sony A1

This lens is one of the best underwater optics ever developed and will grow with you if you upgrade