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Design your dock in 3D
Pick floating, piling or pipe, size the sections, add a boat slip and a lift, set the water — and watch the counts follow underneath. Flotation, pilings and pipe legs are counted from published design guidance and documented industry practice — there is no national dock code, and this page says so rather than inventing one. No account, no card, nothing to install.
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Your dock
Loading your 3D dock…
What this dock takes
8 × 40 ft floating dock · 16 in freeboard · sheltered site
Counted live from the dock above. There is no national dock code — these counts follow published design guidance and documented industry practice, and each states its basis. Counts, not prices: a materials number without labor, permits and site conditions reads like a quote while meaning nothing.
Dock area
320 sq ft
40 ft run · 2 sections
Structure
20 float drums
+ 2 anchor kits — anchoring is trade practice; verify with your marine contractor
Frame
16 members
aluminum frame
Decking
352 sq ft
aluminum panel
Hardware
10 cleats
3 connector kits · 88 lf bumper · 1 ladder
Gangway
12 ft
specify ≥30 psf deck live load (residential basis)
Freeboard at low water
1.33 ft
deck above the water at design low
Site
3–5 ft water
sand bottom · sheltered
The dock above stays in this browser. An account keeps the docks you design there, prices the whole dock, and turns it into a branded proposal with the site conditions and permitting disclosure written in. The full order sheet and CSV export unlock when you pick a plan.
Drag to orbit, and use − / + to zoom. The tools on the dock add slips and lifts and set the sections, the build, the extras and the water; drag the handles to resize it. Reset view frames the whole dock; Below water shows what holds it up. Your dock is kept in this browser; there is no account behind it.
What you do
Choose floating, piling or pipe, lay sections end to end from the shore, set the water depth at seasonal low and high, pick frame and decking, and add a gangway, cleats, bumpers and ladders.
What it works out
Float drums, pilings or pipe legs, frame members, decking area, cleats, connector kits, anchor kits and the gangway — counted from your dimensions, with the basis of each count stated.
What it will not do
Quote you — or tell you that you are permitted. Counts, not prices: a materials number without labor, permits and site conditions reads like a quote while meaning nothing. And the permit word belongs to whoever governs your water; where we hold no rules on file, this page says so instead of guessing.
What it takes to build it
Below is a preview of the takeoff for the dock you drew above — the actual list of things that get delivered, counted, not priced. Edit the design and every count follows. It is the same generator that produces a contractor's order sheet inside deckpro; the complete sheet, priced at a contractor's own supplier costs, is what the paid plans are for.
Structure & flotation
| Item | Qty | Unit |
|---|---|---|
| Foam-Filled Float Drum 24"×48"×16", 500 lb @ full submersion (31.3 psf total flotation vs 28.6 psf required, set by reserve buoyancy — residential basis: 20 psf live, Tier 2; 28 psf published minimum, Tier 3; dead load ≤45% submergence, Tier 3; ≥2" of drum above water at dead + full live, Tier 2; rating: Published full-submersion ratings for 24"×48"×16" drums, Tier 3 documented manufacturer practice) | 20 | ea |
Frame & decking
| Item | Qty | Unit |
|---|---|---|
| Aluminum Frame Member (cut to length, covers 176 lf of rail — side rails 2 per section, cross members @ 4' o.c.; trade practice) | 16 | ea |
+1 more line on the full sheet
Hardware & anchoring
| Item | Qty | Unit |
|---|---|---|
| Anchor Kit — deadweight, chain & shackles (1 per 200 sf, min 2 — trade practice, verify with your marine contractor) | 2 | ea |
| Section Connector / Corner Bracket Kit (1 per section plus 1 per section-to-section joint — trade practice; verify against your dock supplier's connector schedule) | 3 | ea |
| 10" Mooring Cleat (galvanized) — both sides (@ 10' o.c. — trade practice) | 10 | ea |
+4 more lines on the full sheet
Gangway
| Item | Qty | Unit |
|---|---|---|
| Aluminum Gangway 12' × 4' w/ transition plate & handrails (specify ≥30 psf deck live load, residential basis — Tier 2; guards 42–45" — Tier 2, CA DBW 2005 §F2.6.1.2; transition plate ≤1:12 — Tier 2, CA DBW 2005 §F2.11; priced as the book's 4' wide gangway plus each foot past 12' — width is not priced) | 1 | ea |
+1 more line on the full sheet
A preview of the order sheet — counted, not priced. The complete sheet, priced at a contractor’s own supplier costs, is what the paid plans are for.
Where the numbers come from
There is no national dock code. What exists instead is a ladder of authority, and every number on this page names its rung. Three offices decide what you are allowed to build before any engineering starts: your U.S. Army Corps district, your state waterway agency, and local shoreline zoning. They set width, footprint and how far out you may go. The closest things docks have to a published design standard are two public documents: the Defense Department’s UFC 4-152-07 small-craft berthing criteria and California Boating & Waterways’ 2005 marina guidelines — sections you can look up, cite and check us against. Flotation, minimum water depth and pipe-dock limits come from manufacturers who publish their method — named suppliers, published numbers, documented practice.
Float drums are counted to the worst of three criteria. The dock’s dead load alone rides no deeper than 45% of the drum’s height, the middle of the Dock Builders Supply published flotation method: design near 40% submergence, never past 50% (Tier 3 — documented practice). At dead load plus the FULL live load, at least 2 in of the 16 in drum stays above water — the reserve-buoyancy rule (Tier 2 — published guideline: UFC 4-152-07, Design: Small Craft Berthing Facilities §6-3.3.2). And total flotation never drops below the published floor for the load basis: 28 psf residential (Tier 3 — documented practice: Dock Builders Supply) or 40 psf marina (Tier 3 — documented practice: American Muscle Docks). The live load comes from the basis — 20 psf residential (Tier 2 — published guideline: Ameren Lake of the Ozarks Permit Requirements, Appendix B §7.7.1, permit-mandated on that lake only) or 25 psf marina (Tier 2 — published guideline: CA DBW, Layout and Design Guidelines for Marina Berthing Facilities, 2005, §C2.2).
Everything above is published at the dock source register — the documents with their checksums where they have one, and the constants that have no published source, labelled as trade practice rather than dressed in a citation. You can run the flotation math yourself with the free dock flotation calculator.
What actually drives the cost of a dock
Water depth and seasonal range. Depth sets pile and leg length outright, and the seasonal swing between low and high water sizes the gangway — a big range needs a long one — while too little water at seasonal low is what grounds a floating dock's drums. The site drives the structure before any material choice does.
Dock type. Floating docks buy drums and the anchoring to hold them; piling docks buy driven piles and the barge or rig time to drive them; pipe docks are the light seasonal option, but they come out every fall and go back in every spring, and that labor recurs for the life of the dock.
Frame material. Aluminum, steel and pressure-treated wood carry very different dead loads, and on a floating dock the frame is weight the flotation has to carry — a heavier frame means more drums before anyone has stepped aboard. One 8′ × 20′ aluminum-frame section on the residential basis needs 4,571 lb of catalog buoyancy — 10 drums rated 500 lb, set by the reserve buoyancy at full live load. Build the same section in pressure-treated wood and its 13.36 psf dead load raises what the reserve-buoyancy rule asks, from 28.6 to 38.1 psf: 14 drums. The free dock flotation calculator runs the same sizing on your dock and names the criterion that governed.
Exposure and anchoring. Sheltered water forgives; open water works the anchoring on every windy day, and a muck bottom holds deadweight anchors poorly. Anchoring is the line most sensitive to the site — and the one trade practice says to have reviewed rather than guessed.
The gangway. It is priced like a small bridge and rated to the load basis, with handrails, guards and transition plates of its own — on a small dock it can be the single most expensive line after the structure itself.
Then there is labor, freight to the water, permits, and removal each fall where docks come out — a contractor's price is not the material list plus a markup.
Common questions
Is this dock designer really free, with no signup?
Yes. The 3D designer on this page runs in your browser with no account and no card. The one thing that asks for an email address is the optional download, which turns the summary into a one-page plan PDF for your contractor or your permitting office. Your design is kept in this browser — a refresh does not lose it, but it will not follow you to another device. If you want a design kept, priced at a contractor’s own supplier costs and turned into a proposal, that is what the paid contractor plans do.
Is there a building code for docks?
There is no national dock code. A deck has the IRC and a prescriptive span-table guide; a dock has nothing equivalent — no national standard, no span table, no document to certify a dock against. What governs a dock is a three-rung ladder. Rules with legal force come from your U.S. Army Corps district (Section 10 / 404), your state waterway agency, and local shoreline zoning. Below that sit published design guidelines — guidelines, not law. Below that is documented manufacturer practice: published flotation methods, minimum water depths, pipe-dock limits. This designer names which rung every number stands on, and it never claims a dock complies with anything, because there is nothing for it to comply with.
How many float drums does a dock need?
Float drums are counted to the worst of three criteria. The dock’s dead load alone rides no deeper than 45% of the drum’s height, the middle of the Dock Builders Supply published flotation method: design near 40% submergence, never past 50% (Tier 3 — documented practice). At dead load plus the FULL live load, at least 2 in of the 16 in drum stays above water — the reserve-buoyancy rule (Tier 2 — published guideline: UFC 4-152-07, Design: Small Craft Berthing Facilities §6-3.3.2). And total flotation never drops below the published floor for the load basis: 28 psf residential (Tier 3 — documented practice: Dock Builders Supply) or 40 psf marina (Tier 3 — documented practice: American Muscle Docks). The live load comes from the basis — 20 psf residential (Tier 2 — published guideline: Ameren Lake of the Ozarks Permit Requirements, Appendix B §7.7.1, permit-mandated on that lake only) or 25 psf marina (Tier 2 — published guideline: CA DBW, Layout and Design Guidelines for Marina Berthing Facilities, 2005, §C2.2). One 8′ × 20′ aluminum-frame section on the residential basis needs 4,571 lb of catalog buoyancy — 10 drums rated 500 lb, set by the reserve buoyancy at full live load. Build the same section in pressure-treated wood and its 13.36 psf dead load raises what the reserve-buoyancy rule asks, from 28.6 to 38.1 psf: 14 drums. The free dock flotation calculator runs the same sizing on your dock and names the criterion that governed.
Does it give me a material list?
It counts every big category of the dock you drew — drums or pilings or legs, frame members, decking, cleats, connector and anchor kits, the gangway — and previews the line-item order sheet below the designer. The preview fades after the first lines of each section; the complete sheet, every line of it, priced, comes with a paid contractor plan.
Can I get a price for my dock from this?
No — deliberately. This page counts materials; it does not price them. Marine hardware pricing swings by region and season, and labor, freight to the water, permits and anchoring conditions are real costs no web page can know. The number you sign should come from a dock contractor who has seen your shoreline.
Do I need a permit for a dock?
Almost always somebody has a say, and who depends on your water — that is why the designer asks for the state and the kind of water. Where we hold the agency’s own document we name the office and check your dock against its dimensional caps; everywhere else we say we do not have your rules on file and tell you who to ask. We never tell you that you are permitted — that word belongs to the agency.
Build docks for a living?
The paid side keeps the projects, prices them at your supplier costs and margin, and turns them into branded proposals with the site conditions and a shoreline-permitting disclosure written in — plus your own designer link, so a homeowner's dock lands in your pipeline.
Estimate only — not an engineered design. THERE IS NO NATIONAL DOCK CODE: these quantities are sized to documented industry practice and published design guidance — flotation counted in catalog full-submersion ratings but never loaded to them, with a design submergence and reserve freeboard — and not to a prescriptive code table. Each line states the basis it was sized on. Your waterway authority governs: typically the U.S. Army Corps of Engineers district, then your state waterway agency, then local shoreline zoning, each setting its own dimensional limits. Verify everything with your permitting authority and a licensed marine contractor or engineer before ordering or building.