Which bath model will actually cover me in water?

[Skylark9]

All I want is to be covered up to my neck in water. I'm average height, looking for a standard sized bath, yet none of the suppliers can guarantee this? I've got a spreadsheet of all the different dimensions but it's a play between back inclination, bath slope, distance to outflow. If anyone has a bath that covers them nicely please share the model!!

My mum has this, it's called a slipper bath, I love it but am only 5' 3". You can also get a Japanese bath, there's lots of threads on here about the Omni tub I think it's called.

Bette Ocean. Like a normal bath but very deep.
I'd looked into sitting tubs or an ofuro but they were out of my price range.

We have a Burlington 1700mm Hampton back to wall roll top bath, like this but with white feet.
DH is 6'4 and says it's the only bath he's ever been able to float in, it's really deep

https://www.victorianplumbing.co.uk/burlington-hampton-1500mm-showering-bath-with-legs-right-hand-option

Thanks is all that's helpful- I did go down an Ofuro/slipper bath rabbit hole at one point, but need to be practical: there's a shower at one end, and DH has a dodgy knee so can't climb into anything fancy! None of us are over 5' 8'' though, so I'm looking for a rectangular single ended bath that could be 1700 or 1600 long- definitely interested in Bette Ocean. Anyone got experience of Carron? They have a super deep model- Britannia?

It's the measurement from bottom of the bath to the overflow that's important as that defines how deep the water can get.
I think I looked at the brittania, but went for the ocean because I found one in a shop and so could get in and get a proper feel for the depth. I wandered round as many bathroom shops as possible with my tape measure measuring bottom to overflow before choosing