How would I make a stable moving block?

Say I was making a moving pirate ship, how would I made one that moves reasonably fast but you don't fall off it, would I have a low speed, like

speed=(0.1)

But make it replay lots of times over a short amount of time?

CFraming/Positioning it will make players stay in place, since the part is actually teleporting rather than moving (and hence dragging objects along).

Actual motion caused by physics (from setting Velocity or using BodyVelocity or other BodyObjects will let players and objects drag along fairly well with it.

Moderate speeds (> .01 studs / second, < 10 studs / second) and high Friction will help make this more consistent.

Otherwise, you can CFrame the boat and all of the objects resting on top of it (e.g., players or other objects the boat needs to carry), although doing this consistently would be fairly difficult.