diff --git a/lib/www/client/source/src/views/Plan.vue b/lib/www/client/source/src/views/Plan.vue
index 698b456..62a4a80 100644
--- a/lib/www/client/source/src/views/Plan.vue
+++ b/lib/www/client/source/src/views/Plan.vue
@@ -264,7 +264,7 @@ import suncalc from 'suncalc';
 import { mapActions, mapGetters } from 'vuex';
 
 export default {
-  name: "LineList",
+  name: "Plan",
   
   components: {
   },
@@ -369,35 +369,37 @@ export default {
         if (oldVal.value === null) oldVal.value = "";
         
         if (item) {
-          if (oldVal.key == "lagAfter") {
-            // We need to shift the times for every subsequent sequence
-            const delta = oldVal.value*60*1000 - this.lagAfter(item);
-            await this.shiftTimesAfter(item, delta);
-          } else if (oldVal.key == "speed") {
-            const v = oldVal.value*(1.852/3.6)/1000; // m/s
-            const ts1 = new Date(item.ts0.valueOf() + item.length / v);
-            const delta = ts1 - item.ts1;
-            await this.shiftTimesAfter(item, delta);
-            await this.saveItem({sequence: item.sequence, key: 'ts1', value: ts1});
-          } else if (oldVal.key == "sequence") {
-            if (this.shiftAll) {
-              await this.shiftSequences(oldVal.value-item.sequence);
-            } else {
-              await this.shiftSequence(item, oldVal.value);
+          if (item[oldVal.key] != oldVal.value) {
+            if (oldVal.key == "lagAfter") {
+              // Convert from minutes to seconds
+              oldVal.value *= 60;
+            } else if (oldVal.key == "speed") {
+              // Convert knots to metres per second
+              oldVal.value = oldVal.value*(1.852/3.6);
             }
-          } else if (item[oldVal.key] != oldVal.value) {
+            
             if (await this.saveItem(oldVal)) {
               item[oldVal.key] = oldVal.value;
             } else {
               this.edit = oldVal;
             }
+            
           }
         }
+        
       }
     },
 
     async serverEvent (event) {
       if (event.channel == "planned_lines" && event.payload.pid == this.$route.params.project) {
+        
+        // Ignore non-ops
+        /*
+        if (event.payload.old === null && event.payload.new === null) {
+          return;
+        }
+        */
+        
         if (!this.loading && !this.queuedReload) {
           // Do not force a non-cached response if refreshing as a result
           // of an event notification. We will assume that the server has
@@ -582,92 +584,7 @@ export default {
       await this.api([url, init]);
       await this.getPlannedLines();
     },
-
-    async shiftSequences(delta) {
-      const lines = delta < 0
-        ? this.items
-        : [...this.items].reverse(); // We go backwards so as to avoid conflicts.
-
-      for (const line of lines) {
-        const sequence = line.sequence+delta;
-        const url = `/project/${this.$route.params.project}/plan/${line.sequence}`;
-        const init = {
-          method: "PATCH",
-          headers: {"Content-Type": "application/json"},
-          body: {sequence, name: null} // Setting name to null causes it to be regenerated
-        }
-        await this.api([url, init]);
-      }
-    },
-
-    async shiftSequence (item, newSequence) {
-
-      if (item.sequence == newSequence) {
-        // Nothing to do
-        return;
-      }
-
-      const conflict = this.items.find(i => i.sequence == newSequence)
-      if (conflict) {
-        this.showSnack([`Sequence ${newSequence} already exists`, "error"]);
-      } else {
-        // Cannot do this check at the moment as we would have to load the list of sequences.
-        // TODO We will do this after refactoring.
-        /*
-        if (this.sequences.find(i => i.sequence == newSequence)) {
-          this.showSnack([`Sequence ${newSequence} conflicts with a line that's already been acquired`, "warning"]);
-        }
-        */
-
-        const url = `/project/${this.$route.params.project}/plan/${item.sequence}`;
-        const init = {
-          method: "PATCH",
-          headers: {"Content-Type": "application/json"},
-          body: {
-            sequence: newSequence,
-            name: null
-          } // Setting name to null causes it to be regenerated
-        }
-        await this.api([url, init]);
-      }
-    },
-
-    async shiftTimesAfter(item, delta) {
-      const pos = this.items.indexOf(item)+1;
-      if (pos != 0) {
-        const modifiedLines = this.items.slice(pos);
-        if (modifiedLines.length) {
-          modifiedLines.reverse();
-          for (const line of modifiedLines) {
-            const ts0 = new Date(line.ts0.valueOf() + delta);
-            const ts1 = new Date(line.ts1.valueOf() + delta);
-            const url = `/project/${this.$route.params.project}/plan/${line.sequence}`;
-            const init = {
-              method: "PATCH",
-              headers: {"Content-Type": "application/json"},
-              body: {ts1, ts0}
-            }
-            await this.api([url, init]);
-          }
-        }
-      } else {
-        console.warn("Item", item, "not found");
-      }
-    },
-
-    editLagAfter (item) {
-      const pos = this.items.indexOf(item)+1;
-      if (pos != 0) {
-        if (pos < this.items.length) {
-          // Not last item
-          this.editedItems = this.items.slice(pos);
-        } else {
-        }
-      } else {
-        console.warn("Item", item, "not found");
-      }
-    },
-
+    
     editItem (item, key, value) {
       this.edit = {
         sequence: item.sequence,
diff --git a/lib/www/server/lib/db/plan/patch.js b/lib/www/server/lib/db/plan/patch.js
index d324f14..0565e77 100644
--- a/lib/www/server/lib/db/plan/patch.js
+++ b/lib/www/server/lib/db/plan/patch.js
@@ -3,42 +3,221 @@ const { getLineName } = require('./lib');
 
 async function patch (projectId, sequence, payload, opts = {}) {
 	const client = await setSurvey(projectId);
+	
+	sequence = Number(sequence);
+	
+	/*
+	 * Takes a Date object and returns the epoch
+	 * in seconds
+	 */
+	function epoch (ts) {
+		return Number(ts)/1000;
+	}
+	
+	/*
+	 * Shift sequence ts0, ts1 by dt0, dt1 respectively
+	 * for only one sequence
+	 */
+	async function shiftSequence (sequence, dt0, dt1) {
+		const text = `
+			UPDATE planned_lines
+			SET ts0 = ts0 + make_interval(secs => $2), ts1 = ts1 + make_interval(secs => $3)
+			WHERE sequence = $1
+		`;
+		
+		return await client.query(text, [sequence, dt0, dt1]);
+	}
+	
+	/*
+	 * Shift sequence ts0, ts1 by dt0, dt1 respectively
+	 * for all sequences >= sequence
+	 */
+	async function shiftSequences (sequence, dt0, dt1) {
+		const text = `
+			UPDATE planned_lines
+			SET ts0 = ts0 + make_interval(secs => $2), ts1 = ts1 + make_interval(secs => $3)
+			WHERE sequence >= $1
+		`;
+		
+		return await client.query(text, [sequence, dt0, dt1]);
+	}
 
 	try {
 		transaction.begin(client);
+		
+		let deltatime;
+		
+		const r0 = await client.query("SELECT * FROM planned_lines_summary WHERE sequence >= $1 ORDER BY sequence ASC LIMIT 2;", [sequence]);
+		const seq = (r0?.rows || [])[0];
+		if (!seq || seq?.sequence != sequence) {
+			throw {status: 400, message: `Sequence ${sequence} does not exist`};
+		}
+		const seq1 = r0.rows[1];
+		const speed = seq.length/(epoch(seq.ts1)-epoch(seq.ts0)); // m/s
+		
+		if ("ts0" in payload || "ts1" in payload) {
+			/*
+			 * Change in start or end times
+			 */
+			
+			deltatime = "ts0" in payload
+				? (epoch(new Date(payload.ts0)) - epoch(seq.ts0))
+				: (epoch(new Date(payload.ts1)) - epoch(seq.ts1));
+			// Now shift all sequences >= this one by deltatime
+			await shiftSequences(sequence, deltatime, deltatime);
+			
+		} else if ("speed" in payload) {
+			/*
+			 * Change in acquisition speed (m/s)
+			 */
+			
+			// Check that speed is sensible
+			if (payload.speed < 0.1) {
+				throw {status: 400, message: "Speed must be at least 0.1 m/s"};
+			}
+			
+			deltatime = epoch(seq.ts0) + (seq.length/payload.speed) - epoch(seq.ts1);
+			// Fix seq.ts0, shift set.ts1 += deltatime, plus all sequences > this one
+			await shiftSequence(sequence, 0, deltatime);
+			await shiftSequences(sequence+1, deltatime, deltatime);
+			
+		} else if ("fsp" in payload) {
+			/*
+			 * Change of FSP
+			 */
+			
+			// Keep ts1, adjust fsp and ts0 according to speed
+			// ts0' = (shot_distance * delta_shots / speed) + ts0
+			const sign = Math.sign(seq.lsp-seq.fsp);
+			const ts0 = (sign * (seq.length/seq.num_points) * (payload.fsp-seq.fsp) / speed) + epoch(seq.ts0);
+			const text = `
+				UPDATE planned_lines
+				SET fsp = $2, ts0 = $3
+				WHERE sequence = $1;
+			`;
+			await client.query(text, [sequence, payload.fsp, new Date(ts0*1000)]);
+			
+		} else if ("lsp" in payload) {
+			/*
+			 * Change of LSP
+			 */
+			
+			// Keep ts0, adjust lsp and ts1 according to speed
+			// Calculate deltatime from ts1'-ts1
+			// Shift all sequences > this one by deltatime
+			
+			// deltatime = (shot_distance * delta_shots / speed)
+			// ts1' = deltatime + ts1
+			const sign = Math.sign(seq.lsp-seq.fsp);
+			deltatime = (sign * (seq.length/seq.num_points) * (payload.lsp-seq.lsp) / speed);
+			const ts1 = deltatime + epoch(seq.ts1);
+			const text = `
+				UPDATE planned_lines
+				SET lsp = $2, ts1 = $3
+				WHERE sequence = $1;
+			`;
+			await client.query(text, [sequence, payload.lsp, new Date(ts1*1000)]);
+			shiftSequences(sequence+1, deltatime, deltatime);
+			
+		} else if ("lagAfter" in payload && seq1) {
+			/*
+			 * Change of line change time
+			 */
+			
+			// Check that the value is sensible
+			if (payload.lagAfter < 0) {
+				throw {status: 400, message: "Line change time cannot be negative"};
+			}
 
-		const text = `
-			UPDATE planned_lines
-			SET
-				sequence = COALESCE($2, sequence),
-				fsp = COALESCE($3, fsp),
-				lsp = COALESCE($4, lsp),
-				ts0 = COALESCE($5, ts0),
-				ts1 = COALESCE($6, ts1),
-				name = COALESCE($7, name),
-				remarks = COALESCE($8, remarks),
-				meta = COALESCE($9, meta)
-			WHERE sequence = $1;
-		`
+			// Calculate deltatime from next sequence's ts0'-ts0
+			// Shift all sequences > this one by deltatime
+			const ts0 = epoch(seq.ts1) + payload.lagAfter; // lagAfter is in seconds
+			deltatime = ts0 - epoch(seq1.ts0);
+			shiftSequences(sequence+1, deltatime, deltatime);
+			
+		} else if ("sequence" in payload) {
+			/*
+			 * Renumbering / reshuffling of sequences
+			 */
+			
+			// NOTE: This does not enforce consecutive sequences, because sometimes
+			// there is a need for those (don't ask).
+			
+			// Renumber or reorder sequences
+			const r1 = await client.query("SELECT sequence FROM planned_lines ORDER BY sequence;");
+			const sequences = (r1?.rows||[]).map(i => i.sequence);
+			const index = sequences.indexOf(payload.sequence);
+			if (index != -1) {
+				// Make space by shifting all sequence numbers >= payload.sequence by 1
+				const text = `
+					UPDATE planned_lines
+					SET sequence = sequence + 1
+					WHERE sequence >= $1;
+				`;
+				await client.query("SET CONSTRAINTS planned_lines_pkey DEFERRED;");
+				await client.query(text, [payload.sequence]);
+				
+				// And now we need to rename all affected lines
+				const r2 = await client.query("SELECT * FROM planned_lines WHERE sequence > $1 ORDER BY sequence;", [payload.sequence]);
+				for (let row in r2.rows) {
+					const name = await getLineName(client, projectId, row);
+					await client.query("UPDATE planned_lines SET name = $2 WHERE sequence = $1", [row.sequence, name]);
+				}
+				
+			}
+			// Now update just this sequence
+			const text = `
+				UPDATE planned_lines
+				SET sequence = $2
+				WHERE sequence = $1;
+			`;
+			await client.query(text, [sequence, payload.sequence]);
+			
+			// And rename
+			const r3 = await client.query("SELECT * FROM planned_lines WHERE sequence = $1 ORDER BY sequence;", [payload.sequence]);
+			const name = await getLineName(client, projectId, r3.rows[0]);
+			await client.query("UPDATE planned_lines SET name = $2 WHERE sequence = $1", [payload.sequence, name]);
 
-		const p = payload; // For short
-		const values = [ sequence, p.sequence, p.fsp, p.lsp, p.ts0, p.ts1, p.name, p.remarks, p.meta ];
-
-		await client.query(text, values);
-
-		// Magic – if the name is (strictly) null or empty, we generate a new one
-		if (p.name === null || p.name === "") {
-			const text = "SELECT * FROM planned_lines WHERE sequence = $1;";
-			const res = await client.query(text, [p.sequence||sequence]);
-			const row = res.rows[0];
-			const name = await getLineName(client, projectId, row);
-			await client.query("UPDATE planned_lines SET name = $2 WHERE sequence = $1", [p.sequence||sequence, name]);
+			
+		} else if (["name", "remarks", "meta"].some(i => i in payload)) {
+			/*
+			 * Change in various other attributes that do not affect
+			 * other sequences
+			 */
+			
+			// NOTE Magic! If name is empty, we generate one.
+			// Can be used for going back to a default name after it's been
+			// changed manually.
+			if (payload.name === "") {
+				payload.name = await getLineName(client, projectId, r0.rows[0]);
+			}
+			
+			// Change the relevant attribute
+			const text = `
+				UPDATE planned_lines
+				SET
+					name = COALESCE($2, name),
+					remarks = COALESCE($3, remarks),
+					meta = COALESCE($4, meta)
+				WHERE sequence = $1;
+			`;
+			await client.query(text, [sequence, payload.name, payload.remarks, payload.meta]);
+			
+		} else {
+			throw { status: 400, message: "Bad request"};
 		}
 
 		transaction.commit(client);
 	} catch (err) {
 		transaction.rollback(client);
-		throw err;
+		
+		if (err.code == 23503) {
+			if (err.constraint == "planned_lines_line_fsp_class_fkey" || err.constraint == "planned_lines_line_lsp_class_fkey") {
+				throw {status: 400, message: "Attempt to shoot a non-existent shotpoint"};
+			}
+		} else {
+			throw err;
+		}
 	} finally {
 		client.release();
 	}