Hi Don. I plan on diving usually max at 150 ft. but want to be 
    able to settle on the bottom at 5 or 6 hundred without getting crushed. The 
    dive location will be restricted to areas that don't exceed 600. This 
    will require some beefy stiffeners. 
    The saucer design was inspired by one of Jaques Cousteau subs. I don't 
    have a set of plans. 
    I have borrowed extensively from other's designs, adapting them as 
    necessary to fit my goals. There are quite a few saucer shaped hulls that 
    have been built. Some worked and some didn't. I used 3/8 inch steel tubs 
    made of AS516-70 steel because it's an accepted material with a long track 
    record. If I was starting from scratch I'd have used 1/2 inch.
    Although the shape is a little different, the systems are basically the 
    same as a K boat, which has a long track record of reliability. The 
    stiffener ribs are the biggest difference over a K boat. The work involved 
    is quite similar as well. I wanted to sit next to my passenger, which is how 
    I settled on the saucer shape. From my testing, it requires a little more 
    power to move with this shape, so I've made the fairings and ballast tanks 
    as sleek as possible to minimize that. I expect top speed to be around 4 
    knots, but will seldom reach that. These little subs we're building don't go 
    very fast or stay down too long, because of the limited battery power. 
    If you're actually going to build one, ask lots of questions, get the 
    books and stuff from the psubs site. Take the time to learn what's do-able 
    with out spending 3 1/2 million, and then have lots of fun. To me, the 
    design part was the most fun, and took the longest. I built full size 
    mock-ups of different shapes, and once I decided on a saucer, I built scale 
    models in steel to test different aspects. Very time consuming, but well 
    worth it.
    There's an archive section on the psubs site, and although it takes a 
    long time to read, most of your early questions will be answered there. The 
    guys here are all friendly, and very helpful, and we all like thinking about 
    how to solve problems so don't be shy about asking.
    I think one of the first things you need to decide is "what you want 
    your sub to do". Form follows function.
    That more than any thing else will determine what the design will be. 
    There are as many designs as there are guys doing it. 
    There are some basic skills to learn, like welding, electrical, 
    hydraulics, air, machining, etc. but you don't need to be an expert in any 
    of them, just a basic understanding. Most of the stuff we use is "off the 
    shelf" with a little modification. The K boat plans are a little old, and 
    all the guys have modified them to fit their needs, with the availability of 
    new products and tools to make the job of building a little easier. More 
    than any thing else, it's been a learning experience. You can probably 
    expect to spend a minimum of $20K for one, and the sky's the limit if you 
    want extras. That price is with you doing all the work. Add on hiring 
    professionals, and it can get pretty expensive. I know one guy who hired out 
    most of it, and he's near to $70K for just a basic K boat.  
    It's an expensive hobby and not much chance at making money on it 
    without being ABS certified. That cert alone can cost $150K. It all depends 
    on what you want to do with it, and how much you're willing to do your self. 
    I'm not trying to talk you out of it, because it's the most fun I've ever 
    had, but many guys get started and don't finish. Let's face it, It's a 
    complicated little machine, and not really very useful. 
    Perseverance is probably at the top of the list of things you'll 
    need. That, and lots of money. But let me repeat, it's a LOT of fun. 
    Anyway, welcome aboard, and do the homework. Frank 
    D.