I confess I may not be that kind of guy. As regards porta pottis, I confess I like the marine head better but may be in the "beggars can't be choosers" category. I have seen small boats before with marine heads and tanks and since my floor is flat athwartships and only rockered fore and aft I could fit in both easily. Just not sure which is the best way to go. Clearly the potti is more compact though I do have a bit of a height restriction. Peggy, as always, provides expert opinion and food for thought. I'll have to see, I reckon, how it goes. As my old (on both counts) friend Smitty, now burdened with a couple years of Alzheimer's and having trouble formulating sentences, says so often these days, "you gets what you gets and that's all that you gets."
As an aside, let me say about my old friend of forty years and many miles, there never was a better friend, a fine sailor and seaman, and I am so sorry he has come to this in his final years. But..."you gets what you gets.."