One of the first questions asked when potential boat builders stop by is: "Was Trinity built upside-down or right-side up?" As you can see in the photos, right side up. Rather than going into a long discussion of the pros and cons, I'll just state some of the reasons I chose upright.
You can build most anywhere by setting up the wood frame and equally spacing 4 or 5 railroad ties centered and level under the keel. Lay the keel plate on the ties. Hang the ribs from the frame work and you're on your way.
By building upright, the wood frame can be covered for shade and shelter. You're in the sun light and fresh air rather then under the hull. Most of the welding is inside the hull and now in front of you rather then overhead. You will not need a crane to turn the hull over at a cost of a $350.00 an hour.
When fabricating with flat bar and light steel sheets, it's important to think before you weld. Full welds too soon in the process could pull the hull / framing out of alignment. Keep in mind that as the weld cools it shrinks, pulling together or to the welded side. A brace, or a few short tacks on either side, before a full weld will minimize this action. It is best to tack* the complete hull together before finish-welding with the exception of those areas you won't have access to later. Also, if you find you need to make changes, it's much easier to grind off a tack than to cut out a full weld.
Fabrication is as much a thought process as it is construction. Think ahead and plan your progress. Try to consider all the variables. Work from side to side, keeping the hull and the hull stress in balance. Check and double check as you proceed through each stage of construction.
* Tack: a weld 3/8" to 1/2" long.