Security clamp/bracket for 6” jack plate

[Gravygraham]

I’m looking at buying a rib with a 300hp Suzuki mounted on a jack plate, but I’m struggling to find what the deal is regarding securing the engine to the boat to satisfy insurance requirements (and mine of course!). Obvs without the plate you can secure directly through the transom, but this option has been removed.

[HDAV]

Speak to insurer a 300hp motor is a lump you can use locking bolts how is the plate fixed? Is it a movable unit or a transom extension?