This calculator is to be used only as a pre-tonnage evaluator to determine if your vessel may qualify for Coast Guard documentation. Note: Mid Atlantic Sail is in no way affiliated with the US Coast Guard. For determination of your vessels actual tonnage documentation, you will need to use the US Coast Guard's Application for Simplified Measurement. The following is for formulating tonnage of Tug Boats and Barges. If the hull tonnage figures greater than the deck structure, the hull tonnage can be used for documentation. Likewise for the deck structure. If it is determined that the deck structure on the vessel figures greater than the hull, the structure may be used for documentation.