I think it can be quite disconcerting to do a long, free descent in low viz. I didn't like them AT ALL when I was a new diver. Descending along a slope or along an anchor line is much easier, because you have a visual reference at all times.
We don't know where you are, but if there is any shore diving nearby, why don't you start with that? No boat ride to upset your stomach, and you can use the bottom as a reference. We have a lovely local site where one can either swim down from the shoreline, or swim out a bit and do a descent of pretty much any length one wishes. It's a good way to work up to being comfortable with the long fall.
We don't know where you are, but if there is any shore diving nearby, why don't you start with that? No boat ride to upset your stomach, and you can use the bottom as a reference. We have a lovely local site where one can either swim down from the shoreline, or swim out a bit and do a descent of pretty much any length one wishes. It's a good way to work up to being comfortable with the long fall.