There is much ado about "correct" scale for figures, but when I look up and down my street, I see that I am bigger than some of my neighbours while being smaller than others, yet we are all built to the same scale of 12" to the foot. They will be marginally smaller stature without making the boat look like it has been hi-jacked by a school outing. They might well need a bit of repainting/modifying, but we are modellers, not interior decorators, so that should not be a problem.
For 1:40, looking at the railway "O" gauge scale of 1:43 would be near enough. Apart from anything else,they would fit spaces with a bit of spare clearance.