Left Column = Actual Depth of Dive in Feet  --  Top Row = Altitude in Feet
Table Data = Effective Depth for Use in Standard Dive Table

Feet	1000	2000	3000	4000	5000	6000	7000	8000	9000	10000
10	10	11	11	12	12	12	13	13	14	15
20	21	21	22	23	24	25	26	27	28	29
30	31	32	33	35	36	37	39	40	42	44
40	41	43	45	46	48	50	52	54	56	58
50	52	54	56	58	60	62	65	67	70	73
60	62	64	67	69	72	75	78	81	84	87
70	72	75	78	81	84	87	91	94	98	102
80	83	86	89	92	96	100	103	108	112	116
90	93	97	100	104	108	112	116	121	126	131
100	103	107	111	116	120	124	129	134	140	145
110	114	118	122	127	132	137	142	148	153	160
120	124	129	134	139	144	149	155	161	167	174
130	135	140	145	150	156	162	168	175	181	189

Round upward to next 10 feet depth and next 1000 feet altitude.

Instructions: For the altitude of the dive, use your HIGHEST elevation for 24 hours after the dive. Round upward. (For example, if you dive at 6500 feet then drive over a mountain pass at 8900 feet, use 9000 feet as the dive altitude.) Find the appropriate altitude column in the top row. Now find the row with your actual dive depth in the left column. The number where the altitude column intersects the depth row is the adjusted depth. Use this depth in your standard dive table (instead of the actual depth), calculating bottom times, surface intervals, and residual nitrogen as usual.