Sunny weather, a little less work pressure - I can get back to the Ark.
With the middle sealed with epoxy, I ripped the lead weights out of the hull, waggling them with big pliers until the glue holding them in gave way, and set off down to the newly cleaned up garden pool.
Handy hint: The filter sand needs changing every 5 years, not every 15. Makes a difference.
Anyway, I wanted to let the hull sit higher in the water than before, but worried that all the weight of superstructure and animals would make it unstable. At the poolside, I added in a lot less lead, but as far forward as I could, until the boat sat level.
At this point I had to make a decision - the elephants are heavy (who'd have guessed?) and so will affect the trim. From now on, they are the front of the boat so it can be weighted on this basis.
After adding the lead, I sailed for around 10 minutes. Then looked inside.
No water. OK, we've been here before but this time I'm more confident. With 8oz less weight, the model seems to sit on the water and be surprisingly stable. Bashing it against the pool edge didn't threaten to tip it over. Wobbling it about was fine too. Tight turns, and this boat can really turn, don't bother it.
If I really tip the model by hand to the point where the water is at the join between bulwarks and hull then water gets in. But the boat still plops back the right way up. Basically, if the deck is wet, there is water in the hull. I need to be careful.
However, things are looking good.