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November 2025

Lab Update: Trapped Balloon Vacuum Gauge

We added a short guide to the measuring vacuum section that covers the trapped balloon gauge. The write-up walks through how to size the container, prep the airflow holes, and use the balloon expansion as a quick visual check that a bag has pulled down to around 80% of atmospheric pressure.

If you need a reference while setting up a bag, read the new page here: Trapped Balloon Vacuum Gauge.

Research Notes: Comparing Fin Hydrodynamic Kick Resistance

When I talk about how "heavy" a fin feels, what I'm really pointing at is the hydrodynamic resistance the blade builds as it sweeps through the water. The raw feeling is easy to notice, but hard to quantify. To make comparisons across builds, I pulled together a quick benchmark-based model so every fin gets an apples-to-apples resistance score.