20 (日)	02:39	09:02	15:29	21:18
	109cm	19cm	110cm	41cm
大潮 出 04:59 入 18:17 出 03:48 入 16:54 潮干狩り ○ 07:30～10:33

那珂湊（茨城）2031年04月20日の10分毎の潮の高低差を確認できます。
また1日の潮の高低差が1番大きい（潮の流れが大きい）時間に「最大潮位差」と明記してます。

時刻	潮位	高低差	各ポイント
4/20 00:00	79.0	↑3.1
4/20 00:10	82.0	↑3.0
4/20 00:20	85.0	↑3.0
4/20 00:30	87.9	↑2.9
4/20 00:40	90.6	↑2.7
4/20 00:50	93.2	↑2.6
4/20 01:00	95.7	↑2.5
4/20 01:10	98.0	↑2.3
4/20 01:20	100.0	↑2.0
4/20 01:30	101.9	↑1.9
4/20 01:40	103.6	↑1.7
4/20 01:50	105.0	↑1.4
4/20 02:00	106.1	↑1.1
4/20 02:10	107.0	↑0.9
4/20 02:20	107.7	↑0.7
4/20 02:30	108.0	↑0.3	満潮
4/20 02:40	108.1	↑0.1
4/20 02:50	107.9	↓-0.2
4/20 03:00	107.4	↓-0.5
4/20 03:10	106.6	↓-0.8
4/20 03:20	105.6	↓-1.0
4/20 03:30	104.2	↓-1.4
4/20 03:40	102.6	↓-1.6
4/20 03:50	100.8	↓-1.8
4/20 04:00	98.7	↓-2.1
4/20 04:10	96.3	↓-2.4
4/20 04:20	93.8	↓-2.5
4/20 04:30	91.0	↓-2.8
4/20 04:40	88.0	↓-3.0
4/20 04:50	84.9	↓-3.1
4/20 05:00	81.6	↓-3.3
4/20 05:10	78.2	↓-3.4
4/20 05:20	74.7	↓-3.5
4/20 05:30	71.1	↓-3.6
4/20 05:40	67.5	↓-3.6
4/20 05:50	63.8	↓-3.7
4/20 06:00	60.1	↓-3.7
4/20 06:10	56.4	↓-3.7
4/20 06:20	52.8	↓-3.6
4/20 06:30	49.3	↓-3.5
4/20 06:40	45.8	↓-3.5
4/20 06:50	42.4	↓-3.4
4/20 07:00	39.2	↓-3.2
4/20 07:10	36.2	↓-3.0
4/20 07:20	33.3	↓-2.9
4/20 07:30	30.7	↓-2.6
4/20 07:40	28.2	↓-2.5
4/20 07:50	26.0	↓-2.2
4/20 08:00	24.1	↓-1.9
4/20 08:10	22.4	↓-1.7
4/20 08:20	21.0	↓-1.4
4/20 08:30	19.9	↓-1.1
4/20 08:40	19.1	↓-0.8
4/20 08:50	18.7	↓-0.4
4/20 09:00	18.5	↓-0.2	干潮
4/20 09:10	18.6	↑0.1
4/20 09:20	19.0	↑0.4
4/20 09:30	19.7	↑0.7
4/20 09:40	20.8	↑1.1
4/20 09:50	22.1	↑1.3
4/20 10:00	23.7	↑1.6
4/20 10:10	25.6	↑1.9
4/20 10:20	27.7	↑2.1
4/20 10:30	30.1	↑2.4
4/20 10:40	32.7	↑2.6
4/20 10:50	35.5	↑2.8
4/20 11:00	38.5	↑3.0
4/20 11:10	41.7	↑3.2
4/20 11:20	45.0	↑3.3
4/20 11:30	48.4	↑3.4
4/20 11:40	52.0	↑3.6
4/20 11:50	55.6	↑3.6
4/20 12:00	59.2	↑3.6
4/20 12:10	62.9	↑3.7
4/20 12:20	66.7	↑3.8	最大潮位差
4/20 12:30	70.3	↑3.6
4/20 12:40	74.0	↑3.7
4/20 12:50	77.5	↑3.5
4/20 13:00	81.0	↑3.5
4/20 13:10	84.4	↑3.4
4/20 13:20	87.6	↑3.2
4/20 13:30	90.7	↑3.1
4/20 13:40	93.6	↑2.9
4/20 13:50	96.3	↑2.7
4/20 14:00	98.8	↑2.5
4/20 14:10	101.0	↑2.2
4/20 14:20	103.1	↑2.1
4/20 14:30	104.8	↑1.7
4/20 14:40	106.3	↑1.5
4/20 14:50	107.6	↑1.3
4/20 15:00	108.5	↑0.9
4/20 15:10	109.2	↑0.7
4/20 15:20	109.6	↑0.4	満潮
4/20 15:30	109.7	↑0.1
4/20 15:40	109.5	↓-0.2
4/20 15:50	109.0	↓-0.5
4/20 16:00	108.2	↓-0.8
4/20 16:10	107.2	↓-1.0
4/20 16:20	105.9	↓-1.3
4/20 16:30	104.4	↓-1.5
4/20 16:40	102.6	↓-1.8
4/20 16:50	100.6	↓-2.0
4/20 17:00	98.4	↓-2.2
4/20 17:10	96.0	↓-2.4
4/20 17:20	93.4	↓-2.6
4/20 17:30	90.7	↓-2.7
4/20 17:40	87.9	↓-2.8
4/20 17:50	85.0	↓-2.9
4/20 18:00	82.0	↓-3.0
4/20 18:10	78.9	↓-3.1
4/20 18:20	75.8	↓-3.1
4/20 18:30	72.7	↓-3.1
4/20 18:40	69.7	↓-3.0
4/20 18:50	66.6	↓-3.1
4/20 19:00	63.7	↓-2.9
4/20 19:10	60.8	↓-2.9
4/20 19:20	58.1	↓-2.7
4/20 19:30	55.5	↓-2.6
4/20 19:40	53.0	↓-2.5
4/20 19:50	50.8	↓-2.2
4/20 20:00	48.7	↓-2.1
4/20 20:10	46.9	↓-1.8
4/20 20:20	45.3	↓-1.6
4/20 20:30	43.9	↓-1.4
4/20 20:40	42.8	↓-1.1
4/20 20:50	41.9	↓-0.9
4/20 21:00	41.3	↓-0.6
4/20 21:10	41.0	↓-0.3	干潮
4/20 21:20	41.0	0
4/20 21:30	41.2	↑0.2
4/20 21:40	41.7	↑0.5
4/20 21:50	42.5	↑0.8
4/20 22:00	43.5	↑1.0
4/20 22:10	44.8	↑1.3
4/20 22:20	46.3	↑1.5
4/20 22:30	48.1	↑1.8
4/20 22:40	50.1	↑2.0
4/20 22:50	52.3	↑2.2
4/20 23:00	54.6	↑2.3
4/20 23:10	57.2	↑2.6
4/20 23:20	59.9	↑2.7
4/20 23:30	62.7	↑2.8
4/20 23:40	65.6	↑2.9
4/20 23:50	68.6	↑3.0