The shape of the boat, the metal being used to construct the hull, and the particular building method you choose may all contribute to your decision to build the hull upright or inverted. Another factor could be the space and facilities available for turning the hull. There are many simple systems for turning hulls over, so this factor shouldn’t play too big a part in your reaching a decision. You could decide to build two or more rings around your hull, thus facilitating working on the hull and other areas of your boat.

   Advocates of the upside-down method like it because most of the important hull welding can be done in the down-hand position. In any case, some of the welding must be done from inside the hull, including tacking the intermediate stringers to the hull plating. Unfortunately, this may be a bit awkward, but at least some of this welding will have to be done while the hull is still inverted. Leaving the transom off the hull until after turnover will be of some help in gaining access to the interior of the hull. There is some justification for not installing the transom until immediately before the deck is installed.

   In the case of radius-chine construction, I consider it imperative that the hull be built upside down. Building inverted makes it easier to install the radius plating. In our opinion, it’s much simpler to lay the plate onto the framework from above than it is to draw or hold the plating from below until it is tacked in place. At the risk of repetition, you must always build radius-chine hulls upside down. Our preference for building upside down extends to round-bilge hulls as well.

   To be fair to those who prefer to build the hull upright, the stated advantages of this method include the fact that the hull is already in a position to complete the deck superstructure. In other words, it doesn’t have to be turned over. Building the hull upright offers easy access during the entire welding operation. You can overcome some of the disadvantages of not being able to lay the plate on by employing the use of adequate scaffolding. There are also many tricks, such as drilling a hole in the plating and pulling it into position with chains, wedges, and threaded bolts. As mentioned earlier, whether you build upright or upside down will largely depend on your circumstances and personal preference.