AW Hull Builder v1.0.0 – Overview and Quick Start

AW Hull Builder is a paid specialist SketchUp extension with a full 7-day free trial. It supports the early design and drafting of small plywood hard-chine boats by converting corresponding profile and plan curves into an editable three-dimensional hull, with optional deck, transom and internal plywood parts. It can also create developed panels, labelled key drawings, part schedules, stitch-reference marks and suggested 8 ft x 4 ft plywood cutting layouts.

The Hydrostatics workspace provides preliminary fixed-waterline calculations. For a symmetrical monohull it can also combine entered or estimated lightship data with loads assigned to visible SketchUp groups and components to estimate loaded immersion, heel and fore-and-aft trim.

Quick Start

1. Install the final AW Hull Builder RBZ using SketchUp Extension Manager, then close and restart SketchUp.

2. Open Extensions > AW Hull Builder > AW Hull Builder.

3. Draw matching profile and half-plan hull curves at the same scale on one flat drawing plane. At minimum, provide:

   • Profile sheer
   • Profile chine
   • Profile keel/stem
   • Plan sheer
   • Plan chine A straight plan centreline is optional but strongly recommended.

4. Select each source curve, group or component and click its matching Assign button. Corresponding plan and profile curves must describe the same hull and finish at matching longitudinal positions.

5. Choose the station count, bottom construction, mirroring, deck, flat patterns, labels, material information, stitch marks and cutting-layout options. A profile transom and structural inputs may also be assigned.

6. Click Build / Rebuild Hull. The full 7-day free trial starts when the first protected command is used; merely opening the controls or licence status does not start it.

7. Inspect the generated hull, developed panels, key drawings, part schedule and cutting layout. All generated geometry and layouts are preliminary, nominal references and must be checked before material is ordered or cut.

8. Open Extensions > AW Hull Builder > Hydrostatics for preliminary fixed-waterline or loaded calculations. Verify all masses, centres of gravity, water density, assigned load positions and warning messages.

Licensing Commands

Manage Licence opens the SketchUcation licence manager to purchase, activate, inspect or release a licence. Licence / Trial Status reports the current state without starting the local trial.

Optional Companion

AW Editable 3D Text or AW Editable 3D Text Pro can edit the part-reference labels made by Hull Builder. Hull Builder remains fully usable without them.

Important Safety Notice

AW Hull Builder is a design and drafting aid, not naval-architecture software, engineering certification, construction approval or proof that a vessel is safe. Before construction or operation, have every dimension, panel, structure, material, weight, centre of gravity, buoyancy, stability, loading and regulatory requirement checked independently by a suitably qualified naval architect or marine professional.

Consequential Loss

To the fullest extent permitted by applicable law, AW Studio / Andrew Walters will not be liable for any indirect, incidental, special or consequential loss, including loss of profit, revenue, business, opportunity, data, work or materials, arising from use of, inability to use, or reliance on the extension or its output. Nothing in this notice excludes or limits liability that cannot lawfully be excluded or limited, or affects any statutory rights available to a consumer.

AW Hull Builder – Getting Started

Watch the video below for an introduction to AW Hull Builder and a demonstration of the main workflow.

AW Hull Builder v1.0.0 – Main Documentation

Contents

1. What AW Hull Builder does
2. Compatibility and dependencies
3. Installation, trial and licensing
4. Preparing the source drawing
5. Building a hull
6. Deck, transom and structural options
7. Generated output
8. Hydrostatics
9. Updating and rebuilding
10. Important limitations and safety notice

1. What AW Hull Builder Does

AW Hull Builder is a paid specialist SketchUp extension with a full 7-day free trial. It creates early-stage geometric models of small plywood hard-chine boats by combining corresponding curves from an orthographic profile and plan drawing to create the hull sheer, chine bands and keel/stem in three dimensions.

Depending on the selected options, it can create:

• A centreline-seamed V or flat bottom, or a single-piece full-width flat bottom.
• Multiple chine bands when matching additional profile and plan chine curves are supplied.
• A flat, ruled developable or smooth crowned deck.
• Symmetrical hull/deck openings defined in the plan drawing.
• A raked transom from a straight line in the profile drawing.
• Nominal internal plywood parts derived from profile and plan paths, including seats, floors, bulkheads, open frames, keels and longitudinal members.
• Developed hull and deck panels and flat structural-part references.
• Linked SketchUp component instances where an assembled part and its flat pattern are rigidly identical.
• Stable part references, profile and plan key drawings, a part schedule and optional stitch-reference marks.
• Suggested 8 ft x 4 ft plywood cutting layouts, separated by material thickness.
• Preliminary fixed-waterline and loaded heel-and-trim hydrostatic results for supported symmetrical monohulls.

The extension preserves its assigned source information in the SketchUp model. The source curves can therefore be edited and the hull rebuilt using the new geometry and settings.

2. Compatibility and Dependencies

Supported Release Target

• SketchUp 2018 through SketchUp 2026 on Windows.
• SketchUp desktop is required.

The extension is designed to be portable to macOS, but version 1.0.0 has not completed a macOS acceptance pass and is not advertised as Mac-supported.

Dependencies

• No additional extension is required during the built-in 7-day free trial.
• A purchased licence requires the current SketchUcation ExtensionStore / SketchUcation Tools extension, which includes SCFLicense.
• AW Editable 3D Text or AW Editable 3D Text Pro is optional. Either extension can be used to edit Hull Builder's generated editable part labels. Hull Builder can create those labels and remains functional when neither text extension is installed.

3. Installation, Trial and Licensing

Installation

1. Download the official AW Hull Builder RBZ.
2. In SketchUp, open Window > Extension Manager.
3. Click Install Extension and choose the downloaded RBZ.
4. Accept the installation prompt.
5. Close every SketchUp window and restart SketchUp.
6. Open Extensions > AW Hull Builder > AW Hull Builder.

Seven-Day Trial

AW Hull Builder includes a full-featured 7-day free local trial. The trial:

• Starts on the first protected command, such as assigning an input, building a hull or carrying out a protected hydrostatic operation.
• Does not start merely because the Hull Builder panel, Help, About, Manage Licence or Licence / Trial Status is opened.
• Expires seven continuous days after first protected use. Closing SketchUp or reinstalling the extension does not pause or restart it.
• Does not require SketchUcation Tools while it remains active.

Use Extensions > AW Hull Builder > Licence / Trial Status to check the current state without starting the trial.

Purchased Licences

Purchased licences are supplied and managed through SketchUcation SCFLicense. Install the current SketchUcation ExtensionStore / SketchUcation Tools, then choose Extensions > AW Hull Builder > Manage Licence.

Internet access is needed for purchasing, activation, release and other licence-server operations. Once a licence has been activated, SCFLicense can normally check it locally during ordinary use.

Any genuine active licence issued for the AWHullBuilder identifier grants full feature access. The purchased licence takes priority over the local trial. The licence type, duration and number of seats shown by SketchUcation determine the permitted use.

4. Preparing the Source Drawing

Draw the profile and plan at the same scale on one flat SketchUp drawing plane. The default orientation assumes the stern or transom is on the left. If the stern is on the right, enable Reverse stern and bow before building.

Required Inputs

The following five curves are required:

• Profile sheer
• Profile chine
• Profile keel/stem
• Plan sheer
• Plan chine

A straight plan centreline is optional but strongly recommended. If it is not assigned, Hull Builder attempts to infer the centreline from the forward ends of the plan curves.

Each input can be made from connected SketchUp edges, a native SketchUp curve, a group or a component instance. For a clean and reusable drawing, keep each logical curve or path in its own clearly named group or component.

The corresponding plan and profile curves must:

• Describe the same hull at the same scale.
• Run through the same longitudinal range.
• Have matching bow/stem positions.
• Be free from unintended branches, duplicated edges and unrelated geometry.

Select an input curve, group or component and click the corresponding Assign button. The assignment is stored with the model and a top-level assigned group or component remains live-linked for later rebuilds.

Additional Chines

Profile Chine 1 and Plan Chine 1 are the outer or highest chine. For a multi-chine hull, put the remaining profile chines into one assigned profile chine set and the matching plan chines into one assigned plan chine set. The sets must contain the same number of usable paths. Hull Builder sorts them from outside to inside and creates a panel band between each neighbouring rail.

Bottom Construction

Centreline-seamed bottom creates two mirrored bottom panels. They may form a V or lie in one plane to form a flat bottom with a centreline seam.

Single full-width flat bottom creates one chine-to-chine bottom panel when a complete mirrored hull is built. This is suitable for many punts, prams and similar forms.

5. Building a Hull

Basic Workflow

1. Open Extensions > AW Hull Builder > AW Hull Builder.
2. Assign the five required hull curves and preferably the plan centreline.
3. Assign corresponding additional chine sets if required.
4. Choose the bottom construction and whether to create the mirrored hull.
5. Assign any optional transom, deck, opening or structural inputs.
6. Choose the number of stations. More stations can follow the source curves more closely but produce denser geometry and may take longer to build.
7. Enter material-thickness information. Thickness is used for schedules, material estimates and cutting-layout separation; it does not make the generated surfaces physically thick.
8. Choose the flat-pattern, labelling, key-drawing, stitch-reference and plywood cutting-layout options.
9. Click Build / Rebuild Hull.
10. Read every warning and inspect the complete output before relying on it.

Build / Rebuild Hull removes and recreates only geometry previously generated by AW Hull Builder. The source drawing is left in place. Any manual alterations inside generated components should be copied or made only after the final rebuild because rebuilding may replace them.

6. Deck, Transom and Structural Options

Transom

An optional profile transom is defined by one straight edge or a connected collinear chain drawn at the intended rake. Hull surfaces, deck and structural parts are retained on the forward side of the resulting transverse cutting plane. The cut perimeter becomes a nominal transom and flat pattern. The transom top can remain straight or follow the generated deck.

Decks

An optional Deck centreline profile controls the deck height and crown. It should cover the useful hull length and remain at or above the sheer.

Available deck forms are:

• Flat across beam: a simple straight transverse deck.
• Developable half-decks: ruled port and starboard strips which can be unfolded accurately but meet at a small physical centreline ridge.
• Smooth crowned deck: a compound-curved deck with a smooth centreline join. Its developed pattern is necessarily approximate and is produced with a visible finished-edge reference and an oversize trimming allowance.

Hull/Deck Openings

Openings may be assigned from closed plan loops, faces, supported open boundary curves or a selected deck-surface face. The source must be flat and parallel to the main drawing plane. Version 1.0.0 supports centreline-sharing symmetrical openings. Arbitrary isolated off-centre openings require later manual editing.

Internal Plywood Parts

Elements from profile and Elements from plan are optional grouped paths. Profile paths create transverse or horizontal pieces such as seats, floors, bulkheads and frames. Each run can be classified as:

• Horizontal panel
• Solid transverse panel
• Seat front riser
• Open bulkhead / frame
• Ignore

An open bulkhead/frame can include a deck beam or omit the top across a defined deck opening. Check that its entered web width leaves usable hull material and a valid central opening.

Plan paths create vertical longitudinal webs such as keels and stringers. An optional Plan-elements top profile can define their common upper edge. Off-centre parts may be mirrored automatically.

Generated internal parts are nominal zero-thickness references. They are not automatically offset, bevelled, notched or slotted for assembly.

7. Generated Output

Hull and Deck Model

The generated hull uses sampled longitudinal stations and triangulated surface bands. Interior triangulation is normally softened and hidden; enable View > Hidden Geometry only when the underlying mesh needs to be inspected.

Flat Patterns

Hull skins are unfolded by preserving the selected triangle edge lengths. Hull surfaces are not automatically guaranteed to be truly developable, so review the reported development discrepancy and the plotted shapes. The smooth crowned deck is deliberately approximate and must be cut oversize, fitted and trimmed on the assembled hull.

Linked Components

When a planar assembled part is rigidly congruent with its flat form, Hull Builder uses instances of one SketchUp component definition in the assembled model, flat-pattern area and cutting layout. Editing the geometry inside one linked instance updates the others. Developed hull skins and non-planar parts cannot use this rigid link.

References and Schedules

The standard references are:

• HP01, HP02 and onwards: hull panel bands, from sheer towards the bottom
• DK01: deck or deck half
• TR01: transom
• T01, T02 and onwards: parts generated from profile paths
• L01, L02 and onwards: parts generated from plan paths

The same references appear in component names, labels, flat patterns, key drawings, cutting layouts and the part schedule.

Editable Labels

Hull Builder creates editable 3D text metadata for its part labels. AW Editable 3D Text or AW Editable 3D Text Pro is needed only when those labels are to be edited later. Where editable 3D text cannot be created, Hull Builder can fall back to ordinary SketchUp labels and reports the issue.

Plywood Cutting Layout

The optional layout places the required quantities on numbered 96 in x 48 in sheet references, using separate sheet sets for each entered material thickness. Grain-sensitive long parts retain the 8 ft direction where appropriate. The layout audits references and quantities before it is drawn.

The layout uses conservative part envelopes and is a suggested first material arrangement only. It does not interlock every curved outline or prove a minimum sheet count. Long panels may require sheets to be joined into a blank before cutting; the extension does not design scarf, butt-block, puzzle or finger joints.

8. Hydrostatics

Open Extensions > AW Hull Builder > Hydrostatics after building the complete hull. The calculation uses the saved final exterior hull skin and generated transom. Rebuild after editing source curves before recalculating.

Model Axes and Signs

• +X is forward from the generated aft end.
• +Y is port.
• -Y is starboard.
• +Z is upward.
• Negative calculated heel is port down.
• Positive calculated heel is starboard down.

Stage 1 – Fixed Waterline

Stage 1 keeps the hull upright and level. Enter draft above the lowest generated hull point, or select a horizontal line on the original profile drawing. Choose fresh water, seawater or a custom density, then click Calculate.

The result can report:

• Immersed volume and displacement
• Centre of buoyancy
• Waterplane area and centre of flotation
• Wetted exterior area
• Waterline length
• Maximum waterline beam

The immersed exterior and its temporary waterplane cap must form a closed calculation mesh. A submerged opening, panel gap, branched contour or waterline above an open hull edge stops the calculation rather than returning an unchecked volume.

Stage 2 – Loaded Equilibrium

Stage 2 is for a supported port-and-starboard-symmetrical monohull. It combines lightship information with explicit loads and estimates immersion, fore-and-aft trim and heel.

Lightship can be supplied in either of two ways:

• Use the generated plywood-structure estimate and check the entered plywood density, construction allowance and contingency.
• Enter a known manual lightship mass and longitudinal and vertical centres of gravity.

To add a load, create or place a top-level SketchUp group or component, select it, enter its description and mass, then classify it as General load, Fixed ballast or Movable ballast. The object's model-space bounding-box centre is used as its concentrated-load position. Moving the object changes that position the next time Calculate is used.

The entered mass of fixed ballast must not also be included in manual lightship mass. A paired option can represent equal mirrored port and starboard loads. Partially filled tanks and their free-surface effects are not modelled.

The result can include total displacement, combined centre of gravity, heel, trim, centreline drafts, inclined waterplane, open-edge clearance, a small local roll-response check and an optional wider fixed-trim heel sweep. A blue result is an ordinary calculated equilibrium. Amber calls for particular review. A red result may be a non-restoring warning or a diagnostic condition; read its heading carefully. A red failed-case diagnostic is explicitly not a floating equilibrium.

These calculations are preliminary geometric comparisons. They are not a certified free-trim righting-arm or GZ curve, a complete downflooding analysis, a structural assessment or a safe-capacity determination.

9. Updating and Rebuilding

Install a newer RBZ through Extension Manager, then close every SketchUp window and restart SketchUp. Already-open SketchUp sessions can retain previously loaded Ruby code.

Installing an update does not automatically alter an existing generated hull. Use Build / Rebuild Hull when output should be regenerated with the updated version. Save a separate model copy before rebuilding important work.

10. Important Limitations and Safety Notice

AW Hull Builder is a design and drafting aid only. It is not naval-architecture software, engineering certification, construction approval or evidence that a vessel is safe or suitable for construction or operation.

Every generated part remains a nominal zero-thickness reference. Entered material thickness is used for schedules, cutting-layout separation and mass estimation, not for automatic skin offsets, notches, bevels, tabs, joint gaps, stitch holes, kerf, router clearance, holding tabs, fillets or general fabrication allowances.

Before ordering or cutting material, independently verify:

• All source geometry, scales, dimensions and curve correspondence
• Hull fairness and panel developability
• Every flat-pattern perimeter and joining allowance
• Plywood quality, grain, sheet dimensions, thickness and cutting process
• Scantlings, structural strength, joints and construction method
• The complete lightship weight and centre of gravity
• Every load, ballast item and centre-of-gravity position
• Buoyancy, freeboard, stability and downflooding risks
• Applicable construction, operating and regulatory requirements

The software and its output may contain errors or may be unsuitable for a particular vessel, construction method, load case or operating environment. No boat should be built or operated solely in reliance on the extension's output. Any real vessel must be reviewed independently by a suitably qualified naval architect or marine professional and must comply with all applicable standards and legal requirements.

AW Hull Builder is supplied as-is. See the proprietary licence notice included with the extension for the complete licence conditions.

Consequential Loss

To the fullest extent permitted by applicable law, AW Studio / Andrew Walters, the developer, publisher and distributors will not be liable for any indirect, incidental, special or consequential loss, including loss of profit, revenue, business, opportunity, data, work or materials, arising from use of, inability to use, or reliance on AW Hull Builder or its output, whether the claim arises in contract, tort (including negligence), breach of statutory duty or otherwise. Nothing in this documentation or the licence excludes or limits any liability that cannot lawfully be excluded or limited. This clause does not affect any statutory rights available to a consumer.

Copyright 2026 AW Studio / Andrew Walters. All rights reserved.

AW Hull Builder – Release Notes

1.0.2

• General maintenance and internal refinements.

Version 1.0.1

• First public commercial release.
• Creates 3D hard-chine boat hulls, frames and flattened panels from matching 2D plan and profile drawings.
• Includes cutting layouts, preliminary hydrostatics, a full 7-day free trial and SketchUcation licensing.
• Corrects waterplane triangulation for lightly immersed multi-chine hulls.