Wait... I.. can't let that go. This mangaka thinks the gang plank (made of wooden 2x4s) is strong enough to not only support the weight of the fenrir when the boat can't but also to sheer the boat nearly in half (also made of wooden 2x4s). If he had that kind of weight it'd just snap the gang plank, they'd say "well crap now we have to smell wet dog all day" and then they just hop on, jumping the short gap. There's no way the gang plank would do more damage to a boat than a cannon ball!