Sanctuary Boundaries

Map showing sanctuary boundary areas in the northwestern Gulf of Mexico

Flower Garden Banks National Marine Sanctuary has 19 separate boundary areas encompassing all or part of 17 different reefs and banks off the coasts of Texas and Louisiana. Twelve of the banks have individual boundaries, two of the banks have a shared boundary, and three of the banks have two separate boundary areas each.

Boundary Determination

Many of the sanctuary boundaries were drawn close to No Activity Zone (NAZ) designations set by the Bureau of Ocean Energy Management (BOEM). This was done to limit the impact of sanctuary designation on the oil & gas and fishing industries in the northwestern Gulf of Mexico. As a result of this process, Elvers, McGrail, and Parker Banks each have two boundary areas.

Horseshoe Bank was the only bank without a NAZ so the boundary was drawn relatively close to the mapped features in that area. Rankin and 28 Fathom Banks were combined within one boundary due to their close proximity to one another.

You can view the boundary and NAZ data across the whole sanctuary using the Exploration Tool of the Story Map on our home page.

Boundary Points (NAD83)

Maps and sanctuary boundary points for each of the banks are listed below. These are presented in geographic order from the west end to the east end of the sanctuary, starting with Stetson Bank and ending with Alderdice Bank.

GIS boundary data is available for all national marine sanctuaries here:
https://sanctuaries.noaa.gov/library/imast_gis.html

Boundary map of Stetson Bank
Map of Stetson Bank showing the sanctuary boundary. Credit: FGBNMS
Stetson Bank Boundary
Point # Latitude Longitude
1 28.15673 -94.29673
2 28.15661 -94.30312
3 28.15862 -94.30888
4 28.16950 -94.30839
5 28.17386 -94.30257
6 28.17583 -94.29445
7 28.17543 -94.29327
8 28.17284 -94.28952
9 28.16924 -94.28677
10 28.16428 -94.28681
11 28.16274 -94.28756
12 28.15796 -94.29047
13 28.15673 -94.29673
Boundary map of West Flower Garden Bank
Map of West Flower Garden Bank showing the sanctuary boundary. Credit: FGBNMS
West Flower Garden Bank Boundary
Point # Latitude Longitude
1 27.84363 -93.78549
2 27.81750 -93.81056
3 27.81752 -93.84752
4 27.83069 -93.86271
5 27.81735 -93.87490
6 27.83220 -93.89185
7 27.85854 -93.89369
8 27.87925 -93.87853
9 27.92626 -93.82011
10 27.92620 -93.81759
11 27.91801 -93.80801
12 27.90969 -93.77939
13 27.88644 -93.77939
14 27.84363 -93.78549
Boundary map of Horseshoe Bank
Map of Horseshoe Bank showing the sanctuary boundary. Credit: FGBNMS
Horseshoe Bank Boundary
Point # Latitude Longitude
1 27.82317 -93.62789
2 27.80927 -93.63578
3 27.80568 -93.65541
4 27.79429 -93.66555
5 27.78357 -93.68846
6 27.79640 -93.70534
7 27.81855 -93.75198
8 27.82742 -93.74743
9 27.81868 -93.68868
10 27.83143 -93.68941
11 27.84699 -93.70079
12 27.87165 -93.73947
13 27.88602 -93.73294
14 27.87252 -93.64648
15 27.85861 -93.63908
16 27.82317 -93.62789
Boundary map of East Flower Garden Bank
Map of East Flower Garden Bank showing the sanctuary boundary. Credit: FGBNMS
East Flower Garden Bank Boundary
Point # Latitude Longitude
1 27.89455 -93.57040
2 27.87999 -93.61309
3 27.88003 -93.62961
4 27.89330 -93.64172
5 27.92101 -93.64747
6 27.95899 -93.64490
7 27.97485 -93.63086
8 27.98177 -93.60996
9 27.98554 -93.58188
10 27.95206 -93.57810
11 27.92151 -93.56880
12 27.89455 -93.57040
Boundary map of MacNeil Bank
Map of MacNeil Bank showing the sanctuary boundary. Credit: FGBNMS
MacNeil Bank Boundary
Point # Latitude Longitude
1 28.00226 -93.51550
2 27.99707 -93.52669
3 28.00136 -93.52423
4 28.00518 -93.52425
5 28.01694 -93.52233
6 28.01883 -93.51264
7 28.03670 -93.50300
8 28.03724 -93.49844
9 28.03113 -93.49199
10 28.01300 -93.49624
11 28.00331 -93.50725
12 28.00226 -93.51550
Boundary map of Rank & 28 Fathom Banks
Map of Rankin & 28 Fathom Banks showing the sanctuary boundary. Credit: FGBNMS
Rankin & 28 Fathom Banks Boundary
Point # Latitude Longitude
1 27.92554 -93.40593
2 27.92039 -93.41021
3 27.92035 -93.42474
4 27.91387 -93.43165
5 27.90829 -93.42234
6 27.90641 -93.42535
7 27.90489 -93.44219
8 27.89549 -93.44396
9 27.88892 -93.43403
10 27.88072 -93.42805
11 27.87676 -93.42787
12 27.88449 -93.44458
13 27.88803 -93.45159
14 27.88794 -93.45905
15 27.89234 -93.46410
16 27.89971 -93.45571
17 27.90910 -93.45343
18 27.92847 -93.45335
19 27.93407 -93.44743
20 27.93599 -93.44215
21 27.92554 -93.40593
Boundary map of Bright Bank
Map of Bright Bank showing the sanctuary boundary. Credit: FGBNMS
Bright Bank Boundary
Point # Latitude Longitude
1 27.87310 -93.27056
2 27.86549 -93.29462
3 27.87300 -93.31055
4 27.89058 -93.32193
5 27.89839 -93.31987
6 27.90336 -93.30953
7 27.91010 -93.30562
8 27.91634 -93.29292
9 27.91263 -93.28816
10 27.90354 -93.28386
11 27.90253 -93.27238
12 27.89927 -93.26729
13 27.87310 -93.27056
Boundary map of Geyer Bank
Map of Geyer Bank showing the sanctuary boundary. Credit: FGBNMS
Geyer Bank Boundary
Point # Latitude Longitude
1 27.78848 -93.07794
2 27.79458 -93.08448
3 27.83313 -93.07913
4 27.85306 -93.08279
5 27.86328 -93.07885
6 27.86908 -93.06974
7 27.86556 -93.05944
8 27.85211 -93.05391
9 27.83713 -93.05725
10 27.82540 -93.04312
11 27.82490 -93.04276
12 27.80846 -93.03412
13 27.78997 -93.04096
14 27.78602 -93.05384
15 27.78848 -93.07794
Boundary map of Elvers Bank
Map of Elvers Bank showing two separate sanctuary boundaries. Credit: FGBNMS
Elvers Bank Boundary A
Point # Latitude Longitude
1 27.82285 -92.88605
2 27.82087 -92.88600
3 27.82009 -92.88670
4 27.81869 -92.89235
5 27.81690 -92.89404
6 27.81615 -92.89653
7 27.80645 -92.90884
8 27.81221 -92.92082
9 27.81599 -92.93908
10 27.81934 -92.93940
11 27.82250 -92.92465
12 27.82809 -92.91359
13 27.83973 -92.89876
14 27.83972 -92.88038
15 27.83003 -92.86983
16 27.82285 -92.88605

 

Elvers Bank Boundary B
Point # Latitude Longitude
1 27.85645 -92.92310
2 27.85662 -92.91922
3 27.85334 -92.91631
4 27.85076 -92.91727
5 27.84903 -92.92097
6 27.85145 -92.92524
7 27.85645 -92.92310
Boundary map of McGrail Bank
Map of McGrail Bank showing two separate sanctuary boundaries. Credit: FGBNMS
McGrail Bank Boundary A
Point # Latitude Longitude
1 27.97684 -92.58489
2 27.97749 -92.57716
3 27.97475 -92.56753
4 27.97304 -92.56191
5 27.95173 -92.53902
6 27.94849 -92.54254
7 27.96632 -92.56116
8 27.96792 -92.58152
9 27.95989 -92.58187
10 27.95409 -92.57057
11 27.94951 -92.57135
12 27.94920 -92.57994
13 27.95846 -92.60274
14 27.97286 -92.61901
15 27.98096 -92.60158
16 27.97684 -92.58489

 

McGrail Bank Boundary B
Point # Latitude Longitude
1 27.94116 -92.54750
2 27.94180 -92.54543
3 27.94010 -92.54202
4 27.93616 -92.54151
5 27.93481 -92.54398
6 27.93529 -92.54803
7 27.93859 -92.54901
8 27.94116 -92.54750
Boundary map of Sonnier Bank
Map of Sonnier Bank showing the sanctuary boundary. Credit: FGBNMS
Sonnier Bank Boundary
Point # Latitude Longitude
1 28.32652 -92.45356
2 28.32495 -92.45647
3 28.32501 -92.45965
4 28.32796 -92.46626
5 28.33523 -92.47536
6 28.34453 -92.47511
7 28.34840 -92.47439
8 28.35256 -92.47181
9 28.35416 -92.46784
10 28.35456 -92.46135
11 28.35351 -92.45729
12 28.35174 -92.45107
13 28.34852 -92.44564
14 28.34303 -92.44045
15 28.34048 -92.44024
16 28.33584 -92.44669
17 28.33068 -92.44985
18 28.32652 -92.45356
Boundary map of Bouma Bank
Map of Bouma Bank showing the sanctuary boundary. Credit: FGBNMS
Bouma Bank Boundary
Point # Latitude Longitude
1 28.07909 -92.47305
2 28.07370 -92.44900
3 28.07370 -92.44891
4 28.06544 -92.43518
5 28.05162 -92.43380
6 28.03846 -92.44065
7 28.03463 -92.45289
8 28.03114 -92.45537
9 28.02915 -92.46338
10 28.03154 -92.47259
11 28.04166 -92.47229
12 28.04525 -92.46717
13 28.04751 -92.47310
14 28.04676 -92.48308
15 28.04866 -92.48462
16 28.05687 -92.48145
17 28.06388 -92.49262
18 28.07018 -92.49141
19 28.06974 -92.48613
20 28.06594 -92.48098
21 28.07109 -92.47708
22 28.07683 -92.48071
23 28.07909 -92.47305
Boundary map of Rezak Bank
Map of Rezak and Sidner Banks showing the sanctuary boundary for each bank. Credit: FGBNMS
Rezak Bank Boundary
Point # Latitude Longitude
1 27.95420 -92.36641
2 27.95847 -92.37739
3 27.95629 -92.38599
4 27.97297 -92.39248
5 27.97892 -92.39845
6 27.98869 -92.39964
7 27.99372 -92.38244
8 27.98603 -92.36697
9 27.98022 -92.36429
10 27.97442 -92.36996
11 27.96006 -92.36854
12 27.95420 -92.36641

 

Sidner Bank Boundary
Point # Latitude Longitude
1 27.93046 -92.36762
2 27.91368 -92.37398
3 27.91462 -92.38530
4 27.91976 -92.39427
5 27.92306 -92.38792
6 27.94525 -92.38305
7 27.94166 -92.37565
8 27.94231 -92.37189
9 27.93046 -92.36762
Boundary map of Parker Bank
Map of Parker Bank showing two separate sanctuary boundaries. Credit: FGBNMS
Parker Bank Boundary A
Point # Latitude Longitude
1 27.95067 -92.00294
2 27.94177 -91.99762
3 27.93547 -91.99568
4 27.92937 -91.99981
5 27.93224 -92.02999
6 27.93401 -92.03946
7 27.93958 -92.05015
8 27.95012 -92.05050
9 27.96214 -92.05407
10 27.96630 -92.04745
11 27.96869 -92.04120
12 27.96925 -92.02758
13 27.96678 -92.02175
14 27.95067 -92.00294

 

Parker Bank Boundary B
Point # Latitude Longitude
1 27.96082 -91.99450
2 27.96432 -91.99285
3 27.96566 -91.99014
4 27.96385 -91.98600
5 27.96149 -91.98639
6 27.95931 -91.98760
7 27.95824 -91.99183
8 27.96082 -91.99450
Boundary map of Alderdice Bank
Map of Alderdice Bank showing the sanctuary boundary. Credit: FGBNMS
Alderdice Bank Boundary
Point # Latitude Longitude
1 28.09726 -91.99328
2 28.09474 -91.98619
3 28.09569 -91.97526
4 28.09184 -91.97361
5 28.08410 -91.97273
6 28.07506 -91.97457
7 28.07053 -91.98465
8 28.06959 -91.99347
9 28.06819 -92.00512
10 28.07026 -92.01321
11 28.07562 -92.02032
12 28.08058 -92.02436
13 28.08463 -92.02577
14 28.09024 -92.02296
15 28.09487 -92.01231
16 28.09627 -92.00735
17 28.09507 -92.00008
18 28.09726 -91.99328