This model is 200% larger than Vandragon_de' models. While this was not the designers intent, here is a version that holds 2x 20SC containers.

I have also added a path way from the funnel stack to the rudder if you want to add a small balloon and allow the boat to propel it forward. I didn't want to make the funnel larger so I just used a water balloon which sealed fine. I added a infill modifier to the funnel so it would print 95% dense.

Containers designed to hold Micro Machine vehicles and fit with Vandragon_de' ship models (printed at 200%):

https://www.thingiverse.com/thing:6160293