GB/T 20896-2025Small craft - Watertight or quick-draining recesses and cockpits (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document replaces GB/T 20896-2007 "Watertight Stern Compartments and Quick-Drain Stern Compartments for Small Boats" and is consistent with GB/T 20896-2007.

Compared to previous versions, aside from structural adjustments and editorial changes, the main technical changes are as follows.

---The terms "concave body" and "stern compartment" have been changed (see 3.6 and 3.7, 3.8 in the 2007 edition);

---Added multi-bottom concave bodies (see 3.15);

---Added requirements for engine vents installed in recesses (see 6.2);

---The concept of a concave shape to reduce the risk of water immersion has been added (see 7.2);

---Added a recessed area for the foot pedal (see 10.3);

---The data for "minor head loss" has been revised (see Table A.5, Table D.1 in the 2007 edition);

---The phrase "major head loss" has been removed (see D.3 in the 2007 edition).

This document is equivalent to ISO 11812-2020 "Watertight or rapid-drainage depressions for small boats".

The following minimal editorial changes have been made to this document.

---Incorporates the amendments to ISO 11812:2020/Amd.1.2024, indicated by vertical text in the margin of the relevant clauses.

The double lines (||) are marked.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed and is under the jurisdiction of the National Technical Committee on Standardization of Small Boats (SAC/TC241).

1 Scope

This document specifies the watertightness and rapid sluice gate designation for watertight and rapid sluice gates and the stern compartment on small boats with a hull length not exceeding 24m, as well as the procedures for sluice gate operation.

Requirements for space and threshold height, etc. (see reference [1]).

This document covers recesses located on the raised component.

This document does not specify the size, shape, or location of the recess or stern compartment. This document only considers gravity drainage, not drainage via pumps or...

Other methods of draining water.

This document only considers the normal operating conditions of the small boat; the concave body problem of unattended small boats is not within the scope of this document.

This document does not guarantee that water in watertight or rapidly draining recesses or stern compartments will not affect ISO 12217-1, ISO 12217-2, and ISO 12217-3 covers the stability and buoyancy of small boats.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

ISO 9093 Smallcraft - Seacocks and Through-Hulfittings Note. GB/T 19317-2024 Small boat sea-passing plugs and accessories penetrating the hull (ISO 9093:2020, IDT) ISO 8666 Smallcraft Principal Data Note. GB/T 19916-2025 Main data for small boats (ISO 8666:2020, IDT) ISO 12216 Requirements for strength and sealing of windows, portholes, hatch covers, storm covers and doors of smallcraft Note. GB/T 19919-2025 Requirements for strength and sealing of small boat windows, portholes, hatch covers, storm covers and doors (ISO 12216:2020, IDT) ISO 12217-1 Assessment and classification of stability and buoyancy of small boats – Part 1: Non-sailable boats with a hull length of not less than 6 m Note. GB/T 20895.1-2025 Assessment and classification of stability and buoyancy of small boats - Part 1: Non-sailing boats with a hull length of not less than 6 m (ISO 12217-1:2022, IDT) ISO 12217-2 Assessment and classification of stability and buoyancy of small boats – Part 2: Sailboats with a hull length of not less than 6 m (Smal Note. GB/T 20895.2-2025 Assessment and classification of stability and buoyancy of small boats - Part 2: Sailing boats with a hull length of not less than 6 m (ISO 12217-2:2022, IDT) ISO 12217-3 Assessment and classification of stability and buoyancy of small boats – Part 3: Boats with a hull length of less than 6 m (Smalcraft-Note. GB/T 20895.3-2025 Assessment and classification of stability and buoyancy of small boats - Part 3: Boats with a hull length of less than 6m (ISO 12217-3.

2022, IDT)