<p>Seaweed farming, a rapidly growing sector in global food production, offers numerous opportunities for climate adaptation and mitigation, particularly in developed regions. In Morocco, expanding seaweed cultivation holds promise for boosting incomes in fishing communities. This study investigates the effects of water depth (0.2, 0.6, and 1.0 m) on the growth and agar yield of <i>Gracilaria gracilis</i> in Nador Lagoon (35°07’N; 2°52’W) during two periods in 2024, late spring–early summer and late summer–early autumn. Cultivation was conducted using suspended cube structures (1 × 1.2 × 1.5 m) made from PVC tubes and netting. Environmental parameters were continuously monitored, and statistical analysis revealed that temperature (20.3–32.4 °C), dissolved oxygen (5.72–9.55 mg L⁻¹), pH (7.22–8.23), chlorophyll (4.36–104.66 µg L⁻¹), and turbidity (5.06–108.23 NTU) significantly influenced <i>G. gracilis</i> growth. The highest daily growth rate (2.65 ± 0.37% day⁻¹) and maximum agar yield (22.11 ± 0.62% dry weight) were recorded at 0.2 m depth. Additionally, depth significantly influenced agar quality, the highest viscosity (3589 ± 395.98 mPa s) was observed at 1 m under alkaline pretreatment, while the highest melting (86.05 ± 0.07 °C) and gelling temperatures (36.65 ± 1.48°C) were recorded at 0.2 m and 1 m, respectively. As this was a small-scale, exploratory study, the results should be interpreted as preliminary findings. Overall, the results highlight the potential to optimize depth selection to balance both productivity and product quality, offering valuable insights for small-scale farmers in the Nador Lagoon.</p>