After the flip turn water stays inside the POWERBREATHER. How can I improve this?

Crucial for dry flip turns – i.e., after emerging the D-tubes are always free of water – is,
• inhaling sufficient air before the flip turn and
• exhaling the majority of inhaled air only in face-down position – not already in lateral position – through the mouth.
• Tip: The flip turn is even easier with the optional FLIP CAPS. If turning rather left or right, the BLIND CAP can be clipped on alternatively.
Find details regarding “Flip turn and POWERBREATHER” in the user manual.