diff --git a/public/tide-pool-world.js b/public/tide-pool-world.js
index 9bc8593..4dff19c 100644
--- a/public/tide-pool-world.js
+++ b/public/tide-pool-world.js
@@ -698,10 +698,16 @@ function build(world, around) {
   const c = world.creatures.find(o => o.sp === 'artificer');
   if (!c) return;
   const home = { x: c.x, z: c.z };
-  const site = around(1, 3.5, true);
-  if (site) for (let n = 0; n < 90; n++) {
-    c.x = site.x + (world.random() - .5) * 1.6; c.z = site.z + (world.random() - .5) * 1.6;
-    placeBlock(world, c, 0);
+  // A low builder that reaches out rather than up; its children take after it.
+  c.style = { tall: .3, reach: 1.7, dwell: .7, solid: .25 };
+  // It has worked its way along the pool's edge, a part or two at a time, so the structure runs low and long from the rock
+  // out over the water rather than heaping up in one place, and nothing stands more than a few parts above its ground.
+  const from = world.random() * Math.PI * 2, arc = 2.4 + world.random() * .8;
+  for (let n = 0; n < 64; n++) {
+    const a = from + arc * n / 64, r = START_POOL.r * (.78 + .12 * Math.sin(n * .7)) + (world.random() - .5) * .6;
+    c.x = START_POOL.x + Math.cos(a) * r; c.z = START_POOL.z + Math.sin(a) * r * .8;
+    const b = placeBlock(world, c, 0);
+    if (b && b.k - groundLevel(world, b.i, b.j) > 4) removeBlock(world, b);
   }
   for (const b of world.blocks.values()) { b.born = world.time - 60; if (b.kind === 'wheel') b.charge = .8; }
   c.site = null;
diff --git a/public/tide-pool.js b/public/tide-pool.js
index 7450867..1a1f11d 100644
--- a/public/tide-pool.js
+++ b/public/tide-pool.js
@@ -1,7 +1,7 @@
 import {
   createWorld, advanceWorld, offerObject, SPECIES, SPECIES_ORDER, CELL, COLS, ROWS, X0, Z0, X1, Z1, START_POOL, waterLevel, daylight,
   heightAt, surfaceAt, depthAt, onShelf, bodyAt, tideOf, tideRising, label, goalText, describeWorld, creatureById, MACHINES, BLOCK, BLOCK_Y0, blockKey, footAt, debrisAt, footing, stormAt, shineLantern, douseLantern, moonlight, SWELL, swellHeight, cellAt,
-} from './tide-pool-world.js?v=41';
+} from './tide-pool-world.js?v=42';
 
 const root = document.querySelector('[data-tide-pool]');
 const status = document.querySelector('#tide-status');
diff --git a/scripts/tide-pool.test.mjs b/scripts/tide-pool.test.mjs
index 082e5b5..f0f59e1 100644
--- a/scripts/tide-pool.test.mjs
+++ b/scripts/tide-pool.test.mjs
@@ -28,7 +28,8 @@ test('a settled shelf opens lived in: builders at work, a structure in its pool,
   const species = new Set(world.creatures.map(c => c.sp));
   for (const sp of ['scraper', 'tab', 'pylon', 'borer', 'collector', 'artificer']) assert.ok(species.has(sp), `${sp} is already here`);
   assert.ok(!species.has('breaker'), 'the breaker is still to come');
-  assert.ok(world.blocks.size >= 60, `${world.blocks.size} parts stand`);
+  assert.ok(world.blocks.size >= 40, `${world.blocks.size} parts stand`);
+  assert.ok([...world.blocks.values()].every(b => b.k - Math.floor((world.h[b.j * 128 + b.i] + 2.5) / BLOCK) <= 4), "and none stands high");
   assert.ok(world.machines.some(m => m.kind === 'beacon' && m.have >= m.need), 'a finished beacon');
   assert.ok(daylight(world) > .9 && waterLevel(world) < 0, 'afternoon, the tide below half');
   run(world, 30);
diff --git a/src/components/tide-pool.tsx b/src/components/tide-pool.tsx
index 6cd9a80..1922cce 100644
--- a/src/components/tide-pool.tsx
+++ b/src/components/tide-pool.tsx
@@ -191,7 +191,7 @@ export function TidePoolContent() {
         <p id="tide-description" role="status"></p>
         <p>Rendered with Three.js. <a href="/public/tide-pool-three-license.txt">Software license</a>.</p>
       </details>
-      <script type="module" src="/public/tide-pool.js?v=86"></script>
+      <script type="module" src="/public/tide-pool.js?v=87"></script>
     </main>
   );
 }