Title says it all.
The GMG of commander seat is indestructible, cannot be broken by shooting at it. Unlike the GMG on a Ifrit that can be broken or perhaps the weapon system on the MSE-3 Marid.
The HMG on the speedboat is also indestructible unlike static HMG's, Hunter HMG system, automatic HMG's.
Suggestion:
Make it so the GMG and HMG weapons on the speedboat can be disabled by shooting at them.