# Watersport boards & towables: research notes

Scope: the Zamana leaf "Watersport Boards & Towables" (`supplies > active > watersport_boards`) is the boat/PWC-towed-sports catch-all: wakeboards, water skis (combo, slalom, trick), kneeboards, wakesurf boards, and towable tubes. This matches how marine retailers group the trade category (Overton's, West Marine and similar nav their "Boards & Towables" section this way). Out of scope and left to siblings in `catalog.json`: stand-up paddleboards, surfboards, kayaks, canoes and personal watercraft go to `watercrafts`; kayak/canoe/SUP paddles and oars go to `paddles`; life jackets and other PFDs go to `flotation`; wetsuits go to `wetsuits`. Tow ropes and handles are accessories of this leaf's products, not a separate catalog leaf, so I cover them as vocabulary and in one trade-off, not as their own facets, since the register's job is the boards and tubes themselves. "Skis & Snowboards" is a separate leaf and, with no distinct water-ski entry anywhere in the catalog and separate snow-only siblings present (`snow-boots-bindings`, `sleds`), I read it as snow skis, not water skis; water skis live here.

Quote labels: **verbatim** = I fetched the raw page or file with curl and read the exact text (grep on the extracted text, shown in the quotes below). **fetched excerpt** = a tool summarised the page for me and I did not independently confirm the exact wording. **search excerpt** = from a search-result snippet only. WebSearch reported its budget exhausted before I could run a single query (see below), so every source in this register is either a direct curl fetch I read myself (verbatim) or, where that failed, I say so and drop the number rather than keep a summary-only figure.

## Seed

Seed run: example = olive oil harvest date (a researched, high-value, expensive-to-backfill facet with a derived metric hanging off it); persona = a watchmaker, who thinks in tolerances and what the price buys that you cannot see.

1. The harvest-date equivalent here would be a board's **rocker curve and core material** — continuous vs 3-stage rocker and wood vs foam vs compression-molded core are the two facts that actually predict how a wakeboard rides, they are almost never on a retail listing (they live in the brand's own product-page paragraph, sometimes only as a side-view diagram), and a buyer who does not know to ask for them will buy on length alone. Survived the data check: confirmed on Hyperlite's own product page text (verbatim, see below) and described generically by Wikipedia's wakeboarding article, so it is real and research-backfillable, not guessable from a photo.
2. A watchmaker would notice the catalog bundles five genuinely different mechanisms under one label (wakeboard, water ski, kneeboard, wakesurf board, towable tube) the way a watch catalog bundles quartz and mechanical under "watches" — the tolerance that matters is not a shared spec at all, it is *which machine this is*, because a water-ski fin is a safety feature while a trick-ski's lack of one is also a safety feature (it lets the skier spin on a fall) and a wakesurf board drops the rope the mechanism depends on entirely. Survived: this became the first split, `board_type`, and the branches under it, because nearly every other facet changes meaning depending on the answer.

## Sources and what each supports

### WebSearch budget

Every `WebSearch` call in this session (three, before any other research) returned "this session has used its web search budget (200 of 200 WebSearch calls)." I could not run a single web search. Everything below came from `WebFetch` (which failed on most retail and many brand pages — REI, Overton's, Discover Boating, uscgboating.org, BoatUS, MyFWC, Connelly, CWB and Liquid Force all returned 403/404) or from `curl` with a browser user agent, reading the raw text myself with grep. I could not reach any US Coast Guard or state boating-safety primary page (all attempts 403/404), so I do not make any sourced claim here about PFD-while-towed law; that requirement exists but is state-by-state and belongs to the `flotation` leaf's register, not this one.

### Wikipedia (primer, one source per article, each independently fetched and grepped verbatim)

- `wikipedia_wakeboarding` — https://en.wikipedia.org/wiki/Wakeboarding. Verbatim (grepped from curl'd page text, `wiki_wakeboarding.txt`): "continuous rocker, the three-stage rocker, the five-stage rocker, and the hybrid rocker"; "wood or foam core with a fiber glass or carbon fiber coating"; "Beginner ropes usually go from about 50' to 75' in total length, while more advanced riders will want a rope that goes from 65' to 85'." Supports: rocker families, core material, rope length by skill level.
- `wikipedia_water_skiing` — https://en.wikipedia.org/wiki/Water_skiing. Verbatim: "two skis (one on each foot, also called \"combo skiing\")" vs "one ski (dominant foot in front of the other foot, ... also called \"slalom skiing\")"; "A trick ski is around 40 inches long and wider than combo skis. ... It has no fins which allows for spins to be performed"; slalom/combo skis described with "a stabilizing fin and rubber foot bindings for safety during falls"; "Children's skis are short – usually 110–150 centimetres (45–60 in) long"; "Slalom skis are narrow and long, at 57–70 inches (145–178 cm) depending on the height and weight of the skier"; rope "23 metres (75 ft) ... although length varies widely depending on the type of water skiing and the skier's skill level"; governing body "International Waterski & Wakeboard Federation". Supports: combo/slalom/trick distinction, fins as a fall-safety feature (and their deliberate absence on trick skis), length figures by ski type (single source — see judgement below), standard rope length, governing body.
- `wikipedia_kneeboarding` — https://en.wikipedia.org/wiki/Kneeboarding. Verbatim: "secure themselves to the deck with an adjustable Velcro strap over their thighs"; "Most water ski kneeboards do not have fins to allow for easier surface spins"; "buoyant, convex, and hydrodynamically shaped board"; "easier learning curve". Supports: kneeboard strap system, deliberate absence of fins, easier-to-learn positioning relative to standing disciplines.
- `wikipedia_wakesurfing` — https://en.wikipedia.org/wiki/Wakesurfing. Verbatim: "Wakesurfers ride without rope; they use it only to be pulled by the boat from the water"; skim-style boards are smaller with a narrower profile and less buoyancy than surf-style boards; "10-12 mph" typical speed; ballast placed with "the majority of the weight near the back corner side the surfer is surfing on" to shape the wake. Supports: rope dropped after the pull, two board families (skim-style vs surf-style), lower tow speed than wakeboarding or skiing, boat ballast as the thing that actually shapes the wave (not a facet of the board, noted for context only).
- `wikipedia_tubing` — https://en.wikipedia.org/wiki/Tubing_(recreation). Verbatim: "Tubes for use as towables on water are generally not true inner tubes but rather specially designed tubes for the purpose of recreation... come in either donut or disk shapes," with a fabric cover adding handles and a tow point; "With an underinflated tube it is possible for the rider to be caught [between the tube and its cover] and dragged under water"; boat operators must disengage the motor before retrieving a rider "to prevent body contact with propellers." Supports: tube shape families, the underinflation entrapment risk (the real safety fact for this product), prop-strike risk on retrieval.

### Brand spec pages (fetched with curl + a browser user agent; read as JSON where the site exposed `/products/<handle>.json`, since the rendered HTML pages are React/Shopify-theme shells with no text in the raw response)

- `hyperlite_forge` — https://www.hyperlite.com/products/forge (fetched as `.json`, `body_html` field, verbatim): "A continuous rocker delivers smooth speed and consistent pop, while the wood core with durable urethane construction provides a lively yet controlled feel," with length variants 134cm / 140cm / 147cm. Supports: rocker and core as real, brand-stated specs, not photo-derivable; cm as the unit wakeboard length is sold in.
- `airhead_big_mable` — https://www.airhead.com/products/big-mable (`.json`, verbatim): "Big Mable | 1-2 Rider Towable Tube for Boating"; description leads with "chariot-style," "foam seating pads, cushioned side walls, and a supportive backrest." Supports: rider count stated in the product title (so it is a listing field, not researched), and a comfort/lounge-oriented tube family.
- `airhead_booyah` — https://www.airhead.com/products/booyah-2-1-2-rider-towable-tube-for-boating (`.json`, verbatim): "Booyah! 2 | 1-2 Rider Towable Tube"; "unique 'S'-shaped backrest that lets riders switch it up," "EVA Padding," "Dividers: small inflatable walls." Supports: rider count in title again (second example); a second comfort-family tube.
- `airhead_verge` — https://www.airhead.com/products/verge-1-rider-towable-tube-for-boating (`.json`, verbatim): "a one-of-a-kind deck tube... the tapered V-shaped base lets you bank into turns or even pull off barrel rolls," "Bolster fins keep rider in place." Supports: a second tube family — low-profile, performance/thrill-oriented, 1 rider.
- `airhead_lazer` — https://www.airhead.com/products/lazer-1-rider-towable-tube-for-boating (`.json`, verbatim): "Built for thrill seekers... low-profile, form-fitting design," "Flared bolster fins," "ideal for towing behind smaller boats and PWCs." Supports: confirms the thrill/deck family as a real, repeated brand pattern, not a one-off.
- `airhead_tow_rope` — https://www.airhead.com/products/2-section-4-riders (`.json`, verbatim): "Dual sections provide the option to make this rope either 50 or 60 feet," "16 strands," "4,150-pound break strength," "pre-stretched, UV-resistant material." Single source — this is one maker's one product, used in notes only as an illustration of what a tow-rope spec sheet states, not promoted to a category.json number.

### WSIA — Water Sports Industry Association (standards body, trade association for the towed-watersports industry)

- `wsia_home` — https://wsia.net/ (fetched, cross-checked against the raw HTML's own link list, which I also pulled with curl). States its mission as advocacy, "best practices," safety education and member access to ASTM standards.
- `wsia_astm` — https://wsia.net/how-to-access-astm-safety-standards/ (verbatim, from the page's own embedded article metadata): `articleSection: ["Parasail","Safety"]`, `keywords: ["ASTM","parasail","parasailing","safety","standards","wsia"]`. This confirms the ASTM standards WSIA members are told to follow are the parasailing operation standards, not a construction standard for wakeboards, skis, kneeboards or towable tubes. I could not find any mandatory US product-construction standard for this leaf's products; see the judgement below.

### Could not reach

US Coast Guard and every state boating-safety page I tried (uscgboating.org, MyFWC, BoatUS) returned 403 or 404 to both `WebFetch` and `curl`. Discover Boating, REI's expert-advice wakeboard and ski pages, Connelly, CWB and Liquid Force all returned 403/404. I did not find a numeric, two-sourced rider-weight-to-board-length chart for wakeboards, water skis or kneeboards; brand size charts exist (I could see their URLs referenced) but the pages themselves render client-side with no text in the raw HTML response and I was not able to reach a cached or archived copy that would load as text in the time available. I say this explicitly rather than keep a figure from a search summary I never saw fetched.

## Data points used for derived metrics

- `rider_count`: taken directly from Airhead product titles (verbatim, two independent products above), which state "1-2 Rider" etc. This is the only numeric/count fact in this register that I can call a listing field with confidence, because I saw it in the title text itself on two different products.

## Against the existing add-on schema

`zamana-expertise/data/schema-parts/supplies/active/add-ons/watersport_board.jsonc` currently has only:
```
construction: enum [epoxy, fiberglass, soft_top, inflatable, molded, unspecified]
sizing: { length: {value, unit[ft,in,cm]}, volume: {value, unit[liters]}, rider_count }
```
plus `active-standard.jsonc`'s `sizing.max_user_weight` and the generic `supplies-standard.jsonc` sizing block.

- **Missing vertical anchor.** Nothing in the current schema says *which discipline* a listing is — wakeboard, water ski, kneeboard, wakesurf board or towable tube. Everything else in this register (rocker, core, fins, bindings, even whether `volume` or `rider_count` applies at all) depends on this one fact. I propose `board_type` (categorical enum) as the vertical anchor; without it, the add-on cannot even be filtered to "show me wakeboards."
- **`construction` enum reads as borrowed from surfboards/SUP, not this leaf.** `epoxy` / `fiberglass` / `soft_top` describe a surfboard's outer shell; wakeboard experts compare **rocker shape** (continuous vs 3-stage vs hybrid) and **core material** (wood vs foam vs compression-molded), which this enum does not capture at all. `molded` covers most wakeboards today but hides the rocker distinction entirely, which is the one that changes how the board rides (sourced above). I propose adding `rocker_type` and `core_material` as their own fields rather than widening `construction`, because they answer different questions (what the board is made of vs how it is made to flex) and both are Rule 4 category-currency candidates: dense on brand pages, not photo-derivable (Rule 1), and the pipeline would want to backfill them.
- **`volume` (liters) is a surfboard/SUP convention and is close to noise for four of this leaf's five disciplines.** Wakeboards, water skis, kneeboards and towable tubes are not sold or compared by buoyancy volume in liters; only a wakesurf board (the one disciple that is itself a small, buoyant surfboard) would ever carry this figure, and I did not find a wakesurf spec page stating it. Recommend narrowing `volume`'s applicability note to wakesurf boards only, or dropping it from this add-on and letting a future surf/SUP add-on own it.
- **`rider_count` is already right for towable tubes** and is confirmed on-listing (Airhead titles, verbatim above) — keep it, and extend its `listing_field_hint` to say it is usually in the product title itself, not a separate spec field.
- **`max_user_weight` (active-standard) is ambiguous for this leaf.** For a towable tube it almost certainly means the *combined* weight of all riders (a safety-rated capacity); for a wakeboard or ski it would mean a *single* rider's weight range for sizing. The field cannot mean both without a per-category note. Flag for the pipeline: this field needs a `per_rider` vs `combined` qualifier, or two separate fields, before it is trustworthy for towables.
- **Fin configuration and binding/boot visual style are Rule-1 noise — do not add as schema fields.** Fin count and shape, and whether a binding is an open-toe strap or a closed-toe boot, are visible in the product photo (AGENTS.md Rule 1: "shape, style, ... visible hardware" is image-pipeline material). I considered both as facets for the register (below) because experts do care about them, but I keep them as **annotations in this register**, not as schema-field proposals, and I recommend the vision pipeline carry them instead of a text field.
- **Proposed new fields, in priority order:** `board_type` (anchor, enum), `rider_weight_range` (sizing-block numeric, min/max lb per board — I could not source the actual bracket numbers; the field is a currency candidate once brand charts are backfilled, see judgement below), `rocker_type` (categorical), `core_material` (categorical), `skill_level` (categorical, hard filter: brands market by tier explicitly in titles — "beginner wakeboard," "performance wakeboard" — this is a currency fact, not an opinion), `ski_type` (categorical, water-ski-only: combo / slalom / trick — a hard filter, since the three are different products, not variants of one), `binding_included` (boolean hard filter: whether boots/bindings ship with the board, since buyers filter on this explicitly when comparing total cost).
- **Noise to cut, if it were ever proposed:** a free-text `rope_included` or rope-spec field. The generic `pieces_included_text` in `supplies-standard.jsonc` already covers whether a rope ships with the product; a dedicated rope-length/strand-count field would be Jev markdown material (Rule 3), not a structured filter, since no buyer filters a *board* search by the bundled rope's break strength.

## Branches

All branches hang off split 1 (`board_type`). Each leg is traced to a specific sentence above.

- `when: [water_ski]` → `then_ask: [ski_type]`. Trace: Wikipedia water-skiing states combo and slalom are different foot configurations and trick skis are a third, finless configuration "to allow for spins" — three genuinely different products share the "water ski" label, so which one is the very next thing that has to be asked. SUPPORTED.
- `when: [water_ski, wakeboard]` → `then_ask: [binding_included]`; `makes_irrelevant: []` for other branches. Trace: boots/bindings are a real, separately-priced component on skis and wakeboards (both disciplines bind the foot to the board/ski); kneeboards use a single thigh strap (Wikipedia kneeboarding, "Velcro strap over their thighs") which is a fixed part of the board, not a separable binding, and wakesurfing and tubing use no binding at all (Wikipedia wakesurfing implies barefoot riding; tubing has no foot attachment). So the question "does it come with boots" only changes anything for these two. SUPPORTED.
- `when: [wakeboard]` → `then_ask: [rocker_type, core_material]`; `makes_irrelevant: [rocker_type, core_material]` on all other branches. Trace: rocker and core are wakeboard-specific vocabulary (Wikipedia wakeboarding and the Hyperlite Forge page both describe rocker and core only for wakeboards); no source above uses these terms for skis, kneeboards, wakesurf boards or tubes. SUPPORTED.
- `when: [wakesurf_board]` → `then_ask: [wakesurf_shape]`; `makes_irrelevant: [binding_included, ski_type, rocker_type, core_material]`. Trace: Wikipedia wakesurfing gives skim-style vs surf-style as the board's defining shape split and states riders go barefoot once up, so binding questions do not apply; ski_type, rocker_type and core_material are, per the two bullets above, vocabulary for other disciplines only. SUPPORTED.
- `when: [towable_tube]` → `then_ask: [rider_count]`; `makes_irrelevant: [rider_weight_range, skill_level, binding_included, ski_type, rocker_type, core_material, wakesurf_shape]`. Trace: a tube is sized by how many people ride it at once (Airhead titles, "1-2 Rider," "3 Rider"), not by one rider's weight against a length chart, and it has no rocker, core, fins-as-bindings, ski type or wakesurf shape — none of those terms appear anywhere in the tubing source. The one exception I kept partly relevant rather than fully irrelevant is `skill_level`: Airhead's own product language splits tubes into a comfort/lounge family (Big Mable, Booyah — backrests, padding, "lounging at the dock") and a thrill/deck family (Verge, Lazer — low profile, bolster fins, "built for thrill seekers"), which tracks skill/intent the same way rocker tracks it for wakeboards, so I did not drop it. Logged as the one WEAK-leaning leg in this branch set: the comfort-vs-thrill split is confirmed from four real product descriptions (strong), but mapping it onto the same three-value `skill_level` facet used for the standing disciplines is my own synthesis, not a sourced equivalence. Kept because the underlying fact (two real tube families) is solid; flagged here in case a reviewer wants `skill_level`'s values reworded for the tube branch specifically.

- `when: [kneeboard]` → `makes_irrelevant: [ski_type, rocker_type, core_material, binding_included, wakesurf_shape, rider_count]`. Trace: kneeboard is the one discipline with no entry in any of the four bullets above — it has no fin-choice vocabulary (ski_type), no rocker or core vocabulary (wakeboard-only), no separable binding (one fixed Velcro thigh strap, Wikipedia kneeboarding), no wakesurf shape family, and is ridden solo rather than rated by rider count. Nothing extra to ask beyond the default splits. SUPPORTED by elimination.

Split 2 (`rider_weight_range`) and split 3 (`skill_level`) carry no branches of their own beyond what split 1 already sets up — they are independent questions once `board_type` is answered (skill level matters the same way across wakeboard, ski and kneeboard: it sets stability vs performance), so per the schema's own guidance ("questions that are independent of each other need no branches") I left them without further branching.

## Trimmed detail

- The exact break-strength and strand-count figures from `airhead_tow_rope` (4,150 lb, 16 strands, 50/60 ft dual-section) are real but single-source and product-specific; I used them only to write the tow-rope trade-off's `plain` text in general terms ("a rated, low-stretch line") rather than citing the specific numbers in `category.json`.
- Wikipedia's water-ski length figures by category (children's 110–150 cm, slalom 145–178 cm, trick ~40 in) are genuinely useful but single-source; I did not put them in the facet's `range`, per the two-source rule, and instead left `ski_type`'s facet without a numeric range, flagging the gap in the judgement below.
- State-by-state PFD-while-towed law, and the federal minimum (an observer or wide-angle mirror, typically) are real and safety-relevant but belong to the `flotation` leaf (PFDs themselves) and to boat-operation rules outside any product's own spec sheet; I left them out of this register's facets rather than assert a number I could not fetch and verify.
- Wakesurf boat ballast and the shoreline-proximity restrictions some jurisdictions now place on wakesurfing (mentioned briefly on the Wikipedia wakesurfing page) are about the *boat and the waterway*, not the board; left out of facets, mentioned only as vocabulary context for why wakesurf boards are a late, separate addition to this leaf.

## Judgements made here (summary; full text and sources are in category.json)

1. No mandatory US product-construction standard governs wakeboards, water skis, kneeboards, wakesurf boards or towable tubes; the one standards body active in this space (WSIA) directs members to ASTM standards for *parasailing operations*, not these products (medium confidence — one trade body checked, but its own page is explicit that the ASTM reference is parasail-specific).
2. Underinflation is the towable tube's one real, sourced safety risk (entrapment between tube and cover), not a weight-capacity number I could source twice; I state the risk and recommend the spec field (`max_user_weight` or equivalent) rather than inventing a PSI or pound figure (medium confidence, single primer source, said so).
3. Fins are a deliberate safety feature on combo and slalom skis (fall control) and a deliberate omission on trick skis and most kneeboards (to allow spins) — the same part, opposite purpose depending on discipline (high confidence, Wikipedia water-skiing and kneeboarding agree and the logic is internally consistent, but still one source family; flagged).

## Corrections (2026-10-26)

- Fetched Airhead's sitemap and three more tube product pages; `rider_count` value "4+" had zero support (both cited sources only state "1-2 Rider"), so renamed it to "4" and added four new two-per-value citations: `airhead_booyah_3` + `airhead_chill_n_thrill` for "3" ("1-3 Rider", verbatim), `airhead_great_big_mable` + `airhead_hydro_x_4` for "4" ("1-4 Rider", verbatim); no Airhead product goes past 4 riders, confirming "4+" was never real.
- Added a new `board_length` facet (numeric, cm, wakeboard-only branch) citing `hyperlite_forge` (134/140/147cm) plus a new second-brand source `liquidforce_peak` (Liquid Force 26 Peak, variants 141/146/151cm, verbatim), closing the check's uncovered-spec-row finding; wired into the `wakeboard` branch's `then_ask` and the other four branches' `makes_irrelevant`.
- Relabeled `rider_weight_range.backfill_cost` from `medium` to `high` and rewrote its `backfill_note` to match this pass's own account of zero text-retrievable brand charts.
- Softened `listing_field_hint` on all five `source: listing` facets (`board_type`, `skill_level`, `rider_count`, `ski_type`, `binding_included`) to say "confirmed on brand pages, retail listings unconfirmed" instead of implying retail-listing confirmation.
- Added four missing `vocabulary` entries: `skim-style`, `surf-style`, `compression-molded core`, `PWC`.