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Formulae and tables

UNITS OF MEASURMENT

Units of length

  1 metre (m) = 10 decimetres (dm) = 100 centimetres (cm) =1000 millimetres (mm)
1 kilometre (km) = 1000 metres (m)
1 nautical mile = 1852 (m)
1 cable = 185 m
1 fathom  =1.83 m

Conversions between metric and Anglo-American units

 

1 mm

=

0.04 inch (in) or (")
  1 cm = 0.4 incn (in) or (")
  1 cm = 0.03 foot (ft) or (')
  1 m = 3.3 feet (ft) or 0
  1 m = 1.09 yards (yd)
  1 m = 0.55 fathom (fm)
  1 km = 0.54 nautical mile (nm)
  1 km = 0.62 statute mile
       
1 in = 25.4 mm
  1 in = 2.54 cm
  1 ft = 30.5 cm
  1 ft = 0.3 m
  1 yd = 0.9 m
  1 fm = 1.83 m
  1 nautical mile = 1.85 km
  1 statute mile = 1609 m
Quick approximations   10 cm ~ 4 in
    30 cm ~ 1 ft
    1 m ~ 40 in

Units of area

1 square metre (m2) = 100 square decimetres (dm2)
  = 10000 square centimetres (cm2)
  = 1000000 square millimetres (mm2)
1 square kilometre (km2) = 1000000 m2
1 are (a) = 100 m2
1 hectare (ha) = 10000 m2
1 mm2 = 0.0015 in2 Conversions between metric and Anglo-American units
  1 cm2 = 0.15 in2
  1m2 = 10.7 ft2
  1 ha = 2.47 acres
       
1 in2 = 645 mm2
  1 in2 = 6.45 cm2
  1ft2 = 0.09 m2
  1 acre = 0.4 ha
  10 cm b2 ~ 1.5 in2 Quick approximations
  1 dm2 ~ 15 in2
  1m2 ~ 11 ft2
  10 m2 ~ 12 yd2

Units of volume, capacity

  1 cubic metre (m3) = 1000 cubic decimetres (dm3) = 1 000000 cubic centimetres (cm3)
1litre (1) = 1000 cubic centimetres (cm3) = 1 cubic decimetre (dm3)
1 cubic metre (m3) = 1000 litres (1)
Conversions between metric and Anglo-American units 1 cm3 = 0.06 in3
  1 dm3 = 0.03 ft3
  1 m3 = 35.3 ft3
  1 m3 = 1.3 yd3
  1 l = 0.22 gallon (gal)
  1 l = 0.26 US gallon
  1 l = 1.75 pints
  1 l = 2.1 US pints
       
1 in3 = 16.4 cm3
  1 ft3 = 28.3 dm3
  1 ft3 = 0.03 m3
  1 yd3 = 0.76 m3
  1 gal = 4.5 l
  1 US gal = 3.8 l
  1 pint = 0.57 l
  1 US pint = 0.47 l
Quick approximations   9 l ~ 2 gal
  1 m3 ~ 35 ft3

Units of mass, weight and force

Mass and weight

1 kilogram (kg) = 1000 grams
1 tonne or metric ton (†) = 1000 kilograms
1 g = 0.03 ounce (oz) Conversions between metric and Anglo-American units

 

  1 kg = 2.2 pounds (lb)
  1 kg = 0.02 hundred weight (cwt)
  1 t = 0.98 (long) ton
       
1 oz = 28.3 g
  1 lb = 0.45 kg
  1 cwt = 50.8 kg
  1 (long) t = 1.01 t
  10 kg ~ 22 lb Quick Approximations
  50 kg ~ 1 cwt

Force

1 kilogram-force (kgf) = 1000 gram-force (gf)
1 kilogram-force (kgf) = 9.81 newtons (N)
1 decanewton (daN) = 10 newtons (N)

  1 kgf ~ 1 daN Quick Approximation

Units of pressure, power, light and sound

Pressure

FISHERMAN'S WORKBOOK

1 atmosphere (Atm) = 1 kgf/cm2 = 101 kN/m2
~ 1 bar ~ 100000 Pascals (Pa)
~ 1013 millibars (mb)
1 millibar (mb) = 100 N/m2 = 100 Pa
1 kgf/m2 = 9.81 N/m2
1 pound per square inch (PSI) = 689 mb

 

1 kg / mm 2 = 1 422 PSI Conversions between metric and Anglo-American units
  1 PSI = 0.0007 kg / mm2

Power

Power = force x speed
1 horsepower (HP) = 75 kg x m/s
1 kilowatt (kW) = 1.34 Hp
1 HP = 0.74 Kw

Light

The international unit which describes light intensity is the candela (cd).

Illumination (E) is described in terms of units called lux (Lx).

Illumination varies inversely with the square of the distance from the light source; that is, illumination decreases quickly as the light source draws farther away.

FISHERMAN'S WORKBOOK

where r = distance from light source in metres

Sound

The speed of sound in water is approximately 1500 m/s.

Units of speed

1 metre per second (m/s)
1 Knot (kn) = 1 nautical mile per hour* = 1852 m/h = 0.51 m/s

Speed of a vessel

kn ~ m/s ~ km/h ~ Kn ~ m/s ~ km/h
0.5 0.3 0.9 8 4.1 14.8
1 0.5 1.8 8.5 4.4 15.7
1.5 0.8 2.8 9 4.6 16.7
2 1.0 3.7 9.5 4.9 17.6
2.5 1.3 4.6 10 5.1 18.5
3 1.5 5.6 10.5 5.4 19.4
3.5 1.8 6.5 11 5.7 20.4
4 2.1 7.4 11.5 5.9 21.3
4.5 2.3 8.3 12 6.2 22.2
5 2.6 9.3 12.5 6.4 23.1`
5.5 2.8 10.2 13 6.7 24.1
6 3.1 11.1 13.5 6.9 25
6.5 3.3 12 14 7.2 25.9
7 3.6 13 14.5 7.5 26.9
7.5 3.9 13.9 15 7.7 27.8

 

Quick approximations Examples : 10 knots is about equivalent to :
(1) V m/s ~ V kn/2 ~ 10/2 = 5 m/s
(2) V Km/h ~ (V Kn X 2) - 10%(V Kn X 2) ~ (10 X 2) - 10%(10 X 2)= 18 Km/h
(3) V Km/h ~ 1.8 V Kn ~ 1.8 X 10 = 18 Km/h

* Note : in some countries, the distances may be measured in 'statute miles', sometimes referred to simply as 'miles'
1 statute mile
=1609 m = 0.87 nautical mile

Units of temperature

°F

°C

−20

−29.8

−10 −23.3
0 −17.8
10 −12.2
20 −6.7
30 − 1.1
40

4.4

50 10.0
60

15.6

70

24.1

80

26.7

90

32.2

100 37.8
110 43.3
120 48.9
130 54.4
140 60.0
150 65.6
160 71.1
170 76.7
180 27.9
190 87.8
200 93.3
210 98.9

     

°C

°F

−30 −22
−20 −4

− 10

14

0

32

10

50

20

68

30 86
40 104
50 122
60 140
70 158
80 176
90 194
100 212

FISHERMAN'S WORKBOOK

Conversion of kW to HP, and HP to kW

kW

HP

0.2

0.3

0.4

0.5

0.6

0.8

0.8

1.1

1

1.4

2

2.7

4

5.4

6

8.2

8

10.9

10

14

20

27

30

41

40

54

50

68

60

82

70

95

80

109

90

122

100

136

200

272

300

408

400

544

500

680

600

816

700

952

800

1 088

900

1 224

1 000

1 360

1 100

1 496

1 200

1 632

1 300 1 768
1 400

1 904

1 500

2 040

 

HP

kW

0.5

0.4

1

0.7

2

1.5

3

22

4

2.9

5

3.7

6

4.4

8

5.9

10

7.4

20

15

30

22

40

29

60

44

80

59

100

74

200

147

300

221

400

294

500

368

600

442

700

515

800 589
900 662
1 000 736
1 200 883
1 400 1 030
1 600 1 178
1 800 1 325
2 000 1 472

FORMULAE

Area

FISHERMAN'S WORKBOOK

Area, circumference

FISHERMAN'S WORKBOOK

Area, volume

FISHERMAN'S WORKBOOK

Pressure underwater

Depth
(m)

Hydrostatic pressure kgf/cm or atmospheres

0
10
20

1
2 or 1 + 1
3 or 2 + 1

40
50
60

5 or 4 + 1
6 or 5 + 1
7 or 6 + 1

100
200
300

11 or 10 + 1
21 or 20 + 1
31 or 30 + 1

400
500
1000

41 or 40 + 1
51 or 50 + 1
101 or 100 + 1

Pressure (kgf/cm2) = 0.1×depth (m) + 1
(specific gravity of water 0.001 kgf/cm3)

Gravity and buoyancy

Ga (kgf) = weight of a body in air
Ga (kgf) =

volume of the body (m3)×d (specific gravity of the body ii kgf/m3)

F (kgf) = buoyant force
F (kgf) =

volume of thebody(m3)×dw(specific gravity of water i kgf/m3)

Gw (kgf) = weight of the body in water
Gw (kgf) = weight of the body in air (kgf)—buoyant force (kgf)
Gw (kgf) = Ga-F
Gw (kgf) = Ga (1 - 1/d)[for salt water Gw (kgf) = Ga (1 - 1.02/d)]

FISHERMAN'S WORKBOOK

 

Buoyant force is greater than the weight of the body in air.

The. difference [weight of the body in air -buoyant force] is negative.

The body (1) floats.

Buoyant force is equal to the weight of the body in air.

The difference [weight of the body in air -buoyant force] is zero.

The body (2) has neutral buoyancy.

Buoyant force is less than the weight of the body in air.

The difference [weight of the body in air -buoyant force] is positive.

The body (3) sinks.

Square roots of numbers from 0 to 499

           

C3

 

 B2

     A
  N 0 1 2 3 4 5 6 7 8 9
  0.

0,0000

1,0000

1,4142

1,7321

2,0000

2,2361

2,4495

2,6458

2,8284

3,0000

  1.

3,1623

3,3166

3,4641

3,6056

3,7417

3,8730

4,0000

4,1231

4,2426

4,3589

  2.

4,4721

4,5826

4,6904

4,7958

4,8990

5,0000

5,0990

5,1962

5,2915

5,3852

 B 3.

5,4772

5,5678

5,6569

5,7446

5,8310

5,9161

6,0000

6,0828

6,1644

6,2450

  4.

6,3246

6,4031

6,4807

6,5574

6,6332

6,7082

6,7823

6,8557

6,9282

7,0000

  5.

7,0711

7,1414

7,2111

7,2801

7,3485

7,4162

7,4833

7,5498

7,6158

7,6811

  6.

7,7460

7,8102

7,8740

7,9373

8,0000

8,0623

8,1240

8,1854

8,2462

8,3066

  7.

8,3666

8,4261

8,4853

8,5440

8,6023

8,6603

8,7178

8,7750

8,8318

8,8882

  8.

8,9443

9,0000

9,0554

9,1104

9,1652

9,2195

9,2736

9,3274

9,3808

9,4340

  9.

9,4868

9,5394

9,5917

9,6437

9,6954

9,7468

9,7980

9,8489

9,8995

9,9499

  10.

10,0000

10,0499

10,0995

10,1489

10,1980

10,2470

10,2956

10,3441

10,3923

10,4403

  11.

10,4881

10,5357

10,5830

10,6301

10,6771

10,7238

10,7703

10,8167

10,8628

10,9087

  12.

10,9545

11,0000

11,0454

11,0905

11,1355

11,1803

11,2250

11,2694

11,3137

11,3578

  13.

11,4018

11,4455

11,4891

11,5326

11,5758

11,6190

11,6619

11,7047

11,7473

11,7898

  14.

11,8322

11,8743

11,9164

11,9583

12,0000

12,0416

12,0830

12,1244

12,1655

12,2066

  15.

12,2474

12,2882

12,3288

12,3693

12,4097

12,4499

12,4900

12,5300

12,5698

12,6095

  16.

12,6491

12,6886

12,7279

12,7671

12,8062

12,8452

12,8841

12,9226

12,9615

13,0000

  17.

13,0384

13,0767

13,1149

13,1529

13,1909

13,2288

13,2665

13,3041

13,3417

13,3791

  18.

13,4164

13,4536

13,4907

13,5277

13,5647

13,6015

13,6382

13,6748

13,7113

13,7477

  19.

13,7840

13,8203

13,8564

13,8924

13,9284

13,9642

14,0000

14,0357

14,0712

14,1067

  20.

14,1421

14,1774

14,2127

14,2478

14,2829

14,3178

14,3527

14,3875

14,4222

14,4568

  21.

14,4914

14,5258

14,5602

14,5945

14,6287

14,6629

14,6969

14,7309

14,7648

14,7986

  22.

14,8324

14,8661

14,8997

14,9332

14,9666

15,0000

15,0333

15,0665

15,0997

15,1327

  23.

15,1658

15,1987

15,2315

15,2643

15,2971

15,3297

15,3623

15,3948

15,4272

15,4596

  24.

15,4919

15,5242

15,5563

15,5885

15,6205

15,6525

15,6844

15,7162

15,7480

15,7797

  25.

15,8114

15,8430

15,8745

15,9060

15,9374

15,9687

16,0000

16,0312

16,0624

16,0935

  26.

16,1245

16,1555

16,1864

16,2173

16,2481

16,2788

16,3095

16,3401

16,3707

16,4012

  27.

16,4317

16,4621

16,4924

16,5227

16,5529

16,5831

16,6132

16,6433

16,6733

16,7033

  28.

16,7332

16,7631

16,7929

16,8226

16,8523

16,8819

16,9115

16,9411

16,9706

17,0000

  29.

17,0294

17,0587

17,0880

17,1172

17,1464

17,1756

17,2047

17,2337

17,2627

17,2916

  30.

17,3205

17,3494

17,3781

17,4069

17,4356

17,4642

17,4929

17,5214

17,5499

17,5784

  31.

17,6068

17,6352

17,6635

17,6918

17,7200

17,7482

17,7764

17,8045

17,6326

17,8606

C2 32.

17,8885

17,9165

17,9444

17,9722

18,0000

18,0278

18,0555

18,0831

18,1108

18,1364

  33.

18,1659

18,1934

18,2209

18,2483

18,2757

18,3030

18,3303

18,3576

18,3848

18,4120

  34.

18,4391

18,4662

18,4932

18,5203

18,5472

18,5742

18,6011

18,6279

18,6548

18,6815

  35.

18,7083

18,7350

18,7617

18,7883

18,8149

18,8414

18,8680

18,8944

18,9209

18,9473

  36.

18,9737

19,0000

19,0263

19,0526

19,0788

19,1050

19,1311

19,1572

19,1833

19,2094

  37.

19,2354

19,2614

19,2873

19,3132

19,3391

19,3649

19,3907

19,4165

19,4422

19,4679

  38.

19,4936

19,5192

19,5448

19,5704

19,5959

19,6214

19,6469

19,6723

19,6977

19,7231

  39.

19,7484

19,7737

19,7990

19,8242

19,8494

19,8746

19,8997

19,9249

19,9499

19,9750

  40.

20,0000

20,0250

20,0499

20,0749

20,0998

20,1246

20,1494

20,1742

20,1990

20,2237

  41.

20,2485

20,2731

20,2978

20,3224

20,3470

20,3715

20,3961

20,4206

20,4450

20,4695
  42.

20,4939

20,5183

20,5426

20,5670

20,5913

20,6155

20,6398

20,6640

20,6882

20,7123

  43.

20,7364

20,7605

20,7846

20,8087

20,8327

20,8567

20,8806

20,9045

20,9284

20,9523

  44.

20,9762

21,0000

21,0238

21,0476

21,0713

21,0950

21,1187

21,1424

21,1660

21,1896

  45.

21,2132

21,2368

21,2603

21,2838

21,3073

21,3307

21,3542

21,3776

21,4009

21,4243

  46. 21,4476 21,4709 21,4942 21,5174 21,5407 21,5639 21,5870 21,6102 21,6333 21,6564
  47. 21,6795 21,7025 21,7256 21,7486 21,7715 21,7945 21,8174 21,8403

21,8632

21,8861
  48. 21,9089 21,9317 21,9545 21,9773 22,0000 22,0227 22.0454 22,0681

22,0907

22,1133
  49. 22,1359 22,1585

22,1811

22,2036 22,2261 22,2486 22,2711 22,2935 22,3159

22,3383

Using the table : an example

FISHERMAN'S WORKBOOK

Extracted from Statisfique et probabilité from the collection Aide-Mémoire TECHNOR, doc. 15 and 16, Delagrave 1985. With permission of the editor.

Square roots of numbers from 500 to 499

   

B3

         

A3

     
  N 0 1 2 3 4 5 6 7 8 9
  50.

22,3607

22,3830

22,4054

22,4277 22,4499 22,4722 22,4944 22,5167 22,5389 22,5610
  51.

22,5832

22,6053 22,6274 22,6495 22,6716 22,6936 22,7156 22,7376 22,7596 22,7816
  52. 22,8035 22,8254 22,8473 22,8692 22,8910 22,9129 22,9347 22,9565

22,9783

23,0000
  53. 23,0217 23,0434 23,0651 23,0868 23,1084 23,1301 23,1517 23,1733 23,1948 23,2164
  54. 23,2379 23,2594 23,2809 23,3024 23,3238 23,3452 23,3666 23,3880 23,4094 23,4307
  55. 23,4521 23,4734 23,4947 23,5160 23,5372 23,5584 23,5797 23,6008 23,6220 23,6432
  56. 23,6643 23,6854 23,7065 23,7276 23,7487 23,7697 23,7908 23,8118 23,8328 23,8537
A1A2 57. 23,8747 23,8956 23,9165 23,9374 23,9583 23,9792 24,0000 24,0208

24,0416

24,0624
  58. 24,0832

24,1039

24,1247

24,1454

24,1661

24,1868

24,2074

24,2281

24,2487

24,2693

  59.

24,2899

24,3105

24,3311

24,3516

24,3721

24,3926

24,4131

24,4336

24,4540

24,4745

  60.

24,4949

24,5153

24,5357

24,5561

24,5764

24,5967

24,6171

24,6374

24,6577

24,6779

  61.

24,6982

24,7184

24,7386

24,7588

24,7790

24,7992

24,8193

24,8395

24,8596

24,8797

  62.

24,8998

24,9199

24,9399

24,9600

24,9800

25,0000

25,0200

25,0400

25,0599

25,0799

  63.

25,0998

25,1197

25,1396

25,1595

25,1794

25,1992

25,2190

25,2389

25,2587

25,2784

  64.

25,2982

25,3180

25,3377

25,3574

25,3772

25,3969

25,4165

25,4362

25,4558

25,4755

  65.

25,4951

25,5147

25,5343

25,5539

25,5734

25,5930

25,6125

25,6320

25,6515

25,6710

  66.

25,6905

25,7099

25,7294

25,7488

25,7682

25,7876

25,8070

25,8263

25,8457

25,8650

  67.

25,8844

25,9037

25,9230

25,9422

25.9615

25,9808

26,0000

26,0192

26,0384

26,0576

  68.

26,0768

26,0960

26,1151

26,1343

26,1534

26,1725

26,1916

26,2107

26,2298

26,2488

  69.

26,2679

26,2869

26,3059

26,3249

26,3439

26,3629

26,3818

26,4008

26,4197

26,4386

  70.

26,4575

26,4764

26,4953

26,5141

26,5330

26,5518

26,5707

26,5895

26,6083

26,6271

  71.

26,6458

26,6646

26,6833

26,7021

26,7208

26,7395

26,7582

26,7769

26,7955

26,8142

  72.

26,8328

26,8514

26,8701

26,8887

26,9072

26,9258

26,9444

26,9629

26,9815

27,0000

  73.

27,0185

27,0370

27,0555

27,0740

27,0924

27,1109

27,1293

27,1477

27,1662

27,1846

  74.

27,2029

27,2213

27,2397

27,2580

27,2764

27,2947

27,3130

27,3313

27,3496

27,3679

  75.

27,3861

27,4044

27,4226

27,4408

27,4591

27,4773

27,4955

27,5136

27,5318

27,5500

  76.

27,5681

27,5862

27,6043

27,6225

27,6405

27,6586

27,6767

27,6948

27,7128

27,7308

  77.

27,7489

27,7669

27,7849

27,8029

27,8209

27,8388

27,8568

27,8747

27,8927

27,9106

  78.

27,9285

27,9464

27,9643

27,9821

28,0000

28,0179

28,0357

28,0535

28,0713

28,0891

  79.

28,1069

28,1247

28,1425

28,1603

28,1780

28,1957

28,2135

28,2312

28,2489

28,2666

  80.

28,2843

28,3019

28,3196

28,3373

28,3549

28,3725

28,3901

28,4077

28,4253

28,4429

  81.

28,4605

28,4781

28,4956

28,5132

28,5307

28,5482

28,5657

28,5832

28,6007

28,6182

  82.

28,6356

28,6531

28,6705

28,6880

28,7054

28,7228

28,7402

28,7576

28,7750

28,7924

  83.

28,8097

28,8271

28,8444

28,8617

28,8791

28,8964

28,9137

28,9310

28,9482

28,9655

  84.

28,9828

29,0000

29,0172

29,0345

29,0517

29,0689

29,0861

29,1033

29,1204

29,1376

  85.

29,1548

29,1719

29,1890

29,2062

29,2233

29,2404

29,2575

29,2746

29,2916

29,3087

  86.

29,3258

29,3428

29,3598

29,3769

29,3939

29,4109

29,4279

29,4449

29,4618

29,4788

  87.

29,4958

29,5127

29,5296

29,5466

29,5635

29,5804

29,5973

29,6142

29,6311

29,6479

  88.

29,6648

29,6816

29,6985

29,7153

29,7321

29,7489

29,7658

29,7825

29,7993

29,8161

  89.

29,8329

29,8496

29,8664

29,8831

29,8998

29,9166

29,9333

29,9500

29,9666

29,9833

B1B2 90. 30,0000 30,0167 30,0333 30,0500 30,0666 30,0832 30,0998 30,1164

30,1330

30,1496

  91.

30,1662

30,1828

30,1993

30,2159

30,2324

30,2490

30,2655

30,2820

30,2985

30,3150

  92.

30,3315

30,3480

30,3645

30,3809

30,3974

30,4138

30,4302

30,4467

30,4631

30,4795

  93.

30,4959

30,5123

30,5287

30,5450

30,5614

30,5778

30,5941

30,6105

30,6268

30,6431

  94.

30,6594

30,6757

30,6920

30,7083

30,7246

30,7409

30,7571

30,7734

30,7896

30,8058

  95.

30,8221

30,8383

30,8545

30,8707

30,8869

30,9031

30,9192

30,9354

30,9516

30,9677

  96.

30,9839

31,0000

31,0161

31,0322

31,0483

31,0644

31,0805

31,0966

31,1127

31,1288

  97.

31,1448

31,1609

31,1769

31,1929

31,2090

31,2250

31,2410

31,2570

31,2730

31,2890

  98. 31,3050 31,3209 31,3369 31,3528 31,3688 31,3847 31,4006 31,4166 31,4325 31,4484
  99. 31 4643 31,4802 31,4960 31,5119 31,5278 31,5436 31,5595 31,5753 31,5911 31,6070

FISHERMAN'S WORKBOOK

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