Needs that shaped the project
The team’s written January–February 2026 interview summaries describe task-oriented, recreational and research diving perspectives. They are research inputs, not a statistically representative survey or evidence of device performance. Report, stakeholder interviews
| Research perspective | Need reported in the interview summaries | Design response and evidence path |
|---|---|---|
| Search and rescue | Simple, lightweight additions; hands available; no delay to deployment; compatibility with existing equipment | Compatibility, controls, mounting, user validation |
| Recreational diving | Low bulk, reliability, reachable controls and durable equipment | Mass, comfort, battery placement |
| Task-oriented military diving experience | On-demand propulsion and fewer exposed lines; accessible shutdown | Control intent, architecture, fault-test needs |
| Club/research diving | Battery life, speed regulation and low weight | Runtime, battery analysis status, runtime test |
| Reef restoration and surveying | Task applicability, sleek mounting and hands available for work; thigh and tank concepts worth investigating | Mounting decision, compatibility trials |
Market and prior-art research
The April report compared Pegasus Thruster, DiveX BlackTip Travel, LEFEET S1 Pro and TUSA SAV-7 EVO3. Its SWOT, PEST and competitive analyses used cost, hands-free operation, bulk, endurance, component sourcing and acceptance of new equipment to frame the project. These analyses explain why the team pursued a wearable arrangement and a constrained student prototype. They are dated team research, not a current market survey, endorsement or proof that Sea Gliders offers better performance or price. Report, market analysis
The report’s prior-art scan identified wearable and leg-mounted propulsion concepts and recorded publication identifiers US20110174209A1, EP1377478A4 and US20100212571A1. Its useful design lesson was to investigate mounting, controls, shutdown, cable routing and modular integration together. The scan does not establish these publications’ legal status, legal clearance or a novel invention. Report, prior-art scan
The fluid research used two different experimental contexts. Passmore and Rickers studied scuba equipment arrangements with wind-tunnel scale models. Toussaint and colleagues studied active drag during arms-only front-crawl swimming. Both are relevant research references, but neither establishes a universal coefficient for the Sea Gliders geometry. The archive’s coefficient choices and comparisons are documented in A01 and A02. Passmore & Rickers, Toussaint et al.
Documented targets
These are source-defined design targets. The April report primarily addresses the intended two-thruster system; SD2 develops a smaller demonstration prototype. No approved revision reconciles all targets with that later scope. A target and its verification result are separate records.
Force values use newtons (N), pound-force (lbf) or kilogram-force (kgf); kilograms (kg) describe mass.
| Requirement | Documented target and applicable basis | Rationale and verification approach | Available status |
|---|---|---|---|
| R-MASS · mass | Initial ≤6.8 kg (15 lb); revised table ≤3 kg; validation text returns to ≤6.8 kg including battery and mounting | Limit added equipment burden; weigh an explicitly defined complete configuration | Target/basis conflict unresolved; no system weighing record |
| R-THRUST · thrust | Intended pair: 133–156 N peak static; initial sustained target 44.5 N (10 lbf). Presentations also contain differing kgf targets | Size assist propulsion using drag models, then measure the exact hardware in T05 | No measured APISQUEEN thrust; target is not the CFD drag value |
| R-RUNTIME · endurance | ≥60 min cruise assist; initial optional 15–20 min at maximum output | Complete a defined discharge run, T06, for the selected pack and duty | No logged endurance result |
| R-CHARGE · recharge | ≤4 h, dependent on battery and charger | Time recharge from a documented depleted condition to a defined endpoint, T06 | No timed recharge result |
| R-DEPTH · enclosure depth | Approximately 46 m / 150 ft intended; role narrative proposes analysis at 51.72 m as a margin | Establish as-built structural/seal analysis and controlled leak/pressure evidence, A05, T03 | Design target only; no established depth rating |
| R-COMFORT · ergonomics | ≥7.5/10 for the mounted system; presentation criteria include 15° range-of-motion threshold, ≤2 contact points, 2.5–5.1 cm sag, 3 min setup and 20.3 cm entanglement threshold; earlier setup criterion is 2 min | Confirm criterion definitions/direction, then structured trials, T07 | No approved reconciled threshold set or scored diver trial |
| R-BUOYANCY · immersed force | Initial −8.9 N, about −2 lbf | Define sign/configuration and measure immersed weight or displacement | Absent from revised headline metrics; removal does not establish waiver or success |
| R-SIZE · size | Initial overall length <0.61 m / 24 in; minimize protrusion | Measure defined complete configuration and assess interference, T07 | No full-configuration measurement or documented retirement decision |
| R-COST · cost | Initial <$500 with prototype/production phrasing; later metric table omits cost | Specify cost basis before comparing a sanitized spending ledger | Historical estimates include $730 in report and $1,055 in earlier plan; August 26 notes discuss $350 funding. Estimate, funding and actual spend are distinct |
| R-CONTROL · controllability | Variable on-demand thrust, benign startup, emergency off/release and protective shutdown intended | Bench input/fault/stop testing with timing and recovery records, T04; mounted trials, T07 | Preliminary startup/control reported; integrated protections unverified |
| R-COMPAT · compatibility | Hands available; integrate with scuba equipment; avoid snagging and environmental interference | Component fit work T02, followed by defined equipment/user trials T07 | Research need and intended behavior; no demonstrated whole-system compatibility or environmental benefit |
The April report is the primary historical requirements source. Later records describe scope and component changes rather than a formally approved replacement requirements table. Report, scope meetings, SD2 check-ins