diff --git a/olaflow/processing/bathy.py b/olaflow/processing/bathy.py
new file mode 100644
index 0000000..ad61b3e
--- /dev/null
+++ b/olaflow/processing/bathy.py
@@ -0,0 +1,35 @@
+import argparse
+import configparser
+import logging
+import pathlib
+import subprocess
+import tempfile
+import shutil
+
+import numpy as np
+
+parser = argparse.ArgumentParser(
+    description="Convert swash output to olaFlow input"
+)
+parser.add_argument("-v", "--verbose", action="count", default=0)
+args = parser.parse_args()
+
+logging.basicConfig(level=max((10, 20 - 10 * args.verbose)))
+log = logging.getLogger("sws_ola")
+
+log.info("Starting sws -> olaFlow converter")
+config = configparser.ConfigParser()
+config.read("config.ini")
+
+bathy = np.loadtxt(config.get("bathy", "bathy"))
+
+with tempfile.TemporaryDirectory() as tmppath:
+    tmpdir = pathlib.Path(tmppath)
+    np.savetxt(tmpdir.joinpath("bathy.dat"), np.stack((bathy, bathy)))
+    shutil.copy2(
+        pathlib.Path(config.get("bathy", "scad")), tmpdir.joinpath("scad")
+    )
+
+    subprocess.run(("openscad", "scad", "-o", "bathy.stl"), cwd=tmpdir)
+
+    shutil.copy2(tmpdir.joinpath("bathy.stl"), config.get("bathy", "out"))