Water is modeled as an intermediate element between carbon and silicon, with a coarse-grained model (mW) that represents water as a single atom with tetrahedral interactions. This model, based on the Stillinger-Weber potential for silicon, incorporates a nonbond angular dependent term to encourage tetrahedral configurations, mimicking hydrogen-bonded structures without using electrostatics or hydrogen atoms. mW reproduces the energetics, density, and structure of liquid water with high accuracy, at less than 1% of the computational cost of atomistic models. It is particularly useful for studying slow processes in deeply supercooled water, ice nucleation, wetting-drying transitions, and as a realistic water model for coarse-grained simulations of biomolecules and complex materials. The model's success is attributed to the connectivity of molecules rather than the nature of interactions. mW exhibits a density maximum at 4°C, a heat capacity anomaly, and a diffusion anomaly, aligning with experimental data. It also reproduces the liquid-vapor surface tension of water and the structure of ice and low-density amorphous ice. The model's tetrahedral strength is intermediate between silicon and carbon, and it accurately predicts the melting temperature and phase transitions of water. mW outperforms most atomistic models in several key properties, including the density of liquid water, the maximum density, and the liquid-vapor surface tension. However, it slightly overestimates the diffusion coefficient and the density of ice. Despite these minor discrepancies, mW provides a computationally efficient and accurate representation of water, suitable for studying water's behavior in various environments, including aqueous solutions and at interfaces. The model's success highlights the importance of tetrahedral configurations in determining water's structural and thermodynamic properties, and it supports the idea that water's behavior is intermediate between silicon and carbon in terms of tetrahedral interactions.Water is modeled as an intermediate element between carbon and silicon, with a coarse-grained model (mW) that represents water as a single atom with tetrahedral interactions. This model, based on the Stillinger-Weber potential for silicon, incorporates a nonbond angular dependent term to encourage tetrahedral configurations, mimicking hydrogen-bonded structures without using electrostatics or hydrogen atoms. mW reproduces the energetics, density, and structure of liquid water with high accuracy, at less than 1% of the computational cost of atomistic models. It is particularly useful for studying slow processes in deeply supercooled water, ice nucleation, wetting-drying transitions, and as a realistic water model for coarse-grained simulations of biomolecules and complex materials. The model's success is attributed to the connectivity of molecules rather than the nature of interactions. mW exhibits a density maximum at 4°C, a heat capacity anomaly, and a diffusion anomaly, aligning with experimental data. It also reproduces the liquid-vapor surface tension of water and the structure of ice and low-density amorphous ice. The model's tetrahedral strength is intermediate between silicon and carbon, and it accurately predicts the melting temperature and phase transitions of water. mW outperforms most atomistic models in several key properties, including the density of liquid water, the maximum density, and the liquid-vapor surface tension. However, it slightly overestimates the diffusion coefficient and the density of ice. Despite these minor discrepancies, mW provides a computationally efficient and accurate representation of water, suitable for studying water's behavior in various environments, including aqueous solutions and at interfaces. The model's success highlights the importance of tetrahedral configurations in determining water's structural and thermodynamic properties, and it supports the idea that water's behavior is intermediate between silicon and carbon in terms of tetrahedral interactions.