Core Parameters a RIB General Arrangement Drawing Must Show

What Is a General Arrangement Drawing?

The General Arrangement (GA) drawing is the single most important technical document for a RIB boat. It defines the overall layout, principal dimensions, and key specifications. For buyers, it is the first engineering document they request. For manufacturers, it is the reference document that every other drawing and specification traces back to. A GA that omits required parameters creates confusion, delays quotations, and undermines technical credibility.

Title Block Requirements

Every GA drawing must carry a title block containing:

• Model name and variant — e.g., "Paddle Board Overstock RIB 450 Patrol"
• Drawing number — unique identifier with revision code
• Scale — primary scale and any detail view scales
• Units — primary measurement system stated explicitly
• Date and revision history — current revision date and summary of changes
• Drawn by / Checked by / Approved by — responsible engineering personnel
• Material classification — hull material (GRP / Aluminum) and tube material (PVC / Hypalon)

LOA vs LH: A Critical Distinction

• LOA (Length Overall) — the maximum length of the boat including all permanently attached fittings, railings, and tube extensions. This is the transport and storage dimension.
• LH (Length of Hull) — the length of the hull structure measured per ISO 8666, excluding removable fittings and tube overhang. This is the design and classification dimension.

RCD design category and ISO standard references use LH. Shipping and trailering calculations use LOA. A GA must show both, clearly labeled. Confusing these values is a frequent source of compliance errors.

Dual Units: Millimeters and Feet/Inches

International RIB buyers work in metric. US and some Commonwealth buyers work in imperial. A professional GA provides both:

• Primary dimensions in millimeters — per ISO drawing conventions
• Secondary dimensions in feet and inches — in parentheses or on alternate dimension lines
• Weight in kilograms and pounds — light displacement and maximum load
• Speed in knots — universally understood in marine applications

Draft Conditions

A RIB GA must show draft in two conditions:

• Light ship draft — hull and tube only, no payload, fuel at minimum
• Maximum load draft — at declared maximum load per the builder plate

Both values affect operational planning and must be labeled with the corresponding displacement.

Capacity and Power Box

The GA must include a capacity and power information box, typically placed near the title block, containing:

• Maximum number of persons
• Maximum load in kilograms
• Maximum engine power in kilowatts and horsepower
• Maximum engine weight in kilograms
• Design category (A, B, C, or D)

These values must match the builder plate and DoC exactly.

Standard / Optional / Project-Specific Legend

A GA shows the baseline configuration. Clearly distinguish:

• Standard equipment — shown in solid lines, included in base specification
• Optional equipment — shown in dashed lines or hatched, available at additional cost
• Project-specific items — shown in phantom lines, customized per buyer requirements

This prevents scope disputes and clarifies what the quoted price includes.

What NOT to Show on a Public GA

Public-facing GA drawings — those on websites or in brochures — must exclude:

• Structural scantling details (laminate schedules, alloy thicknesses)
• Internal framing and structural reinforcement locations
• Bond line and adhesive joint specifications
• Tube chamber pressure specifications
• Detailed electrical and plumbing routing

These details belong in the confidential technical file shared under NDA only.

Create professional GA drawings that build buyer confidence. Visit Paddle Board Overstock Technical Drawings for RIB GA templates and dimensioning standards.