Collapse to view only § 178.440 - Drainage of open boats.
- § 178.410 - Drainage of flush deck vessels.
- § 178.420 - Drainage of cockpit vessels.
- § 178.430 - Drainage of well deck vessels.
- § 178.440 - Drainage of open boats.
- § 178.450 - Calculation of drainage area for cockpit and well deck vessels.
§ 178.410 - Drainage of flush deck vessels.
(a) Except as provided in paragraph (b) of this section, the weather deck on a flush deck vessel must be watertight and have no obstruction to overboard drainage.
(b) Each flush deck vessel may have solid bulwarks in the forward one-third length of the vessel if:
(1) The bulwarks do not form a well enclosed on all sides; and
(2) The foredeck of the vessel has sufficient sheer to ensure drainage aft.
§ 178.420 - Drainage of cockpit vessels.
(a) Except as follows, the cockpit on a cockpit vessel may be watertight:
(1) A cockpit may have companionways if the companionway openings have watertight doors, or weathertight doors and coamings which meet § 179.360 of this subchapter.
(2) A cockpit may have ventilation openings along its inner periphery if the vessel operates only on protected or partially protected waters.
(b) The cockpit deck of a cockpit vessel that operates on exposed or partially protected waters must be at least 255 millimeters (10 inches) above the deepest load waterline unless the vessel complies with:
(1) The intact stability requirements of §§ 170.170, 170.173, 171.050, 171.055, and 171.057 in subchapter S of this chapter;
(2) The Type II subdivision requirements in §§ 171.070, 171.072, and 171.073 in subchapter S of this chapter; and
(3) The damage stability requirements in § 171.080 in subchapter S of this chapter.
(c) The cockpit deck of a cockpit vessel that does not operate on exposed or partially protected waters must be located as high above the deepest load waterline as practicable.
(d) The cockpit must be self-bailing. Scuppers or freeing ports for the cockpit deck of a cockpit vessel must:
(1) Be located to allow rapid clearing of water in all probable conditions of list and trim;
(2) Have a combined drainage area of at least the area required by § 178.450 of this part; and
(3) If the deck is less than 255 millimeters (10 inches) above the deepest load waterline of the vessel, be fitted with non-return devices.
§ 178.430 - Drainage of well deck vessels.
(a) The weather deck on a well deck vessel must be watertight.
(b) The area required on a well deck vessel for drainage of well formed by the bulwarks shall be determined by § 178.450.
(c) The freeing ports or scuppers on a well deck vessel must be located to allow rapid clearing of water in all probable conditions of list and trim.
(d) The deck of well deck vessel that operates on exposed or partially protected waters must be at least 255 millimeters (10 inches) above the deepest load waterline unless the vessel complies with:
(1) The intact stability requirements of §§ 170.170, 170.173, 171.050, 171.055, and 171.057 in subchapter S of this chapter;
(2) The Type II subdivision requirements in §§ 171.070, 171.072, and 171.073 in subchapter S of this chapter; and
(3) The damage stability requirements in § 171.080 in subchapter S of this chapter.
§ 178.440 - Drainage of open boats.
The deck within the hull of an open boat must drain to the bilge. Overboard drainage of the deck is not permitted.
§ 178.450 - Calculation of drainage area for cockpit and well deck vessels.
(a) The drainage area required on a vessel must be computed using the following formula:
For protected waters required drainage = .1 × Basic Drainage For partially protected waters required drainage = .5 × Basic Drainage For exposed waters required drainage = Basic Drainage where: Basic Drainage area in centimeters 2 = 4389.12 × [(Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio)]; or Basic Drainage area in inch 2 = (Recess Volume × Recess Ratio) + (Weather Deck Volume × Weather Deck Ratio) Recess Volume = (B(b) Vessels with bulwarks in the forward part of the vessel shall not form a well with the deckhouse which retains water.