How Hood's bow-wave trough could expose lower hull

Was Hood's lower hull exposed because its bow rose out of the water at speed?

The explanation is the trough behind the bow wave, which lowers the water locally and can expose less-protected hull.

Hood's apparent exposure of lower hull is explained by the wave pattern along its side. The water rises in the bow wave and then falls in the trough behind it. That local fall can reveal plating below the main armour belt while the ship remains a displacement vessel. Battlecruisers sometimes carried a thin lower belt or omitted it to save weight, leaving less protection in that area.