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Over 50 years of Trusted Marine Service

Seacocks & Thru-Hulls

Marine Plumbing

Seacocks, Thru-Hulls, Strainers & Below-Waterline Fittings

Shop marine seacocks, thru-hull fittings, raw-water strainers, valves, guards, fittings, and installation supplies for intake, discharge, drainage, and cooling systems.

Browse Products Pumps & Plumbing Ask Parts Desk
SeacocksShutoff valves for intake and discharge points below the waterline. Thru-Hull FittingsBronze, stainless, nylon, straight, angled, and mushroom-head fittings. Raw-Water StrainersProtect engines, pumps, generators, and air conditioning systems. Valves & FittingsAdapters, elbows, hose tails, drains, and plumbing connection parts. Sealants & BeddingMarine sealants for bedding hardware and fittings. Guards & ProtectionDrip guards and small protection pieces around hull fittings.

Below-Waterline Parts Need Careful Matching

Confirm hose inside diameter, thread type, material compatibility, bonding requirements, valve access, and whether the fitting is above or below the waterline. When in doubt, match the existing fitting and ask for help before replacing critical hull plumbing.

Filters

Groco #304 Stainless Steel Filter Basket For ARG Strainers

Groco #304 Stainless Steel Filter Basket For ARG Strainers

$157.39 - $157.39
$157.39
$157.39 - $157.39
$157.39
Item locally warehoused

Spare Basket

$157.39 - $157.39
$157.39
$157.39 - $157.39
$157.39
Groco ARG503 Sight Glass With Drain Plug For ARG Strainer

Groco ARG503 Sight Glass With Drain Plug For ARG Strainer

$98.69 - $98.69
$98.69
$98.69 - $98.69
$98.69
Item locally warehoused

For the ARG series strainers. Maximum psi is 50. Maximum temperature is 225° F. Sight glass includes drain wingnut.

$98.69 - $98.69
$98.69
$98.69 - $98.69
$98.69
Groco ARG Strainer Cap, 1/2"

Groco ARG Strainer Cap, 1/2"

$40.29 - $40.29
$40.29
$40.29 - $40.29
$40.29
Item locally warehoused

PC non-meatallic strainer cap.

$40.29 - $40.29
$40.29
$40.29 - $40.29
$40.29
Groco #304 Stainless Steel Filter Basket

Groco #304 Stainless Steel Filter Basket

$97.39 - $97.39
$97.39
$97.39 - $97.39
$97.39
Item locally warehoused

Spare Basket

$97.39 - $97.39
$97.39
$97.39 - $97.39
$97.39
Groco Polyethylene Filter Basket

Groco Polyethylene Filter Basket

$127.39 - $127.39
$127.39
$127.39 - $127.39
$127.39
Item locally warehoused

Spare Basket

$127.39 - $127.39
$127.39
$127.39 - $127.39
$127.39
Groco ARG1503 Sight Glass With Drain Plug For ARG Strainer

Groco ARG1503 Sight Glass With Drain Plug For ARG Strainer

$233.19 - $233.19
$233.19
$233.19 - $233.19
$233.19
Item locally warehoused

For the ARG series strainers. Maximum psi is 50. Maximum temperature is 225° F. Sight glass includes drain wingnut.

$233.19 - $233.19
$233.19
$233.19 - $233.19
$233.19
Groco Polyethylene Filter Basket For ARG Strainer

Groco Polyethylene Filter Basket For ARG Strainer

$113.09 - $113.09
$113.09
$113.09 - $113.09
$113.09
Item locally warehoused

Spare Basket

$113.09 - $113.09
$113.09
$113.09 - $113.09
$113.09
Groco Polyethylene Filter Basket

Groco Polyethylene Filter Basket

$94.49 - $94.49
$94.49
$94.49 - $94.49
$94.49
Item locally warehoused

Spare Basket

$94.49 - $94.49
$94.49
$94.49 - $94.49
$94.49
Groco ARG1253 Sight Glass With Drain Plug For ARG Strainer

Groco ARG1253 Sight Glass With Drain Plug For ARG Strainer

$161.79 - $161.79
$161.79
$161.79 - $161.79
$161.79
Item locally warehoused

For the ARG series strainers. Maximum psi is 50. Maximum temperature is 225° F. Sight glass includes drain wingnut.

$161.79 - $161.79
$161.79
$161.79 - $161.79
$161.79
Groco BV Bronze Full-Flow Flanged Ball-Type Seacock

Groco BV Bronze Full-Flow Flanged Ball-Type Seacock

$513.19 - $513.19
$513.19
$513.19 - $513.19
$513.19
Item locally warehoused

Features patented field-selectable and changeable direction of rotation-permits installation in otherwise unusable locations. Tri-flange base and m...

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$513.19 - $513.19
$513.19
$513.19 - $513.19
$513.19
Groco BM5 Monel Filter Basket

Groco BM5 Monel Filter Basket

$363.19 - $363.19
$363.19
$363.19 - $363.19
$363.19
Item locally warehoused

Spare Basket

$363.19 - $363.19
$363.19
$363.19 - $363.19
$363.19
Groco BM3 Monel Filter Basket

Groco BM3 Monel Filter Basket

$285.09 - $285.09
$285.09
$285.09 - $285.09
$285.09
Item locally warehoused

Spare Basket

$285.09 - $285.09
$285.09
$285.09 - $285.09
$285.09
Groco FTH Bronze Flush Thru-Hull With Nut

Groco FTH Bronze Flush Thru-Hull With Nut

$41.59 - $41.59
$41.59
$41.59 - $41.59
$41.59
Item locally warehoused

Includes locknut.Bronze.NOT TO BE USED IN POTABLE WATER SYSTEMS.

$41.59 - $41.59
$41.59
$41.59 - $41.59
$41.59
Flojet 01740014 90 Degree Strainer

Flojet 01740014 90 Degree Strainer

$74.59 - $74.59
$74.59
$74.59 - $74.59
$74.59
Item locally warehoused

Fine 40 mesh stainless steel filter screen prevents breakdowns from particles in the water. Transparent housing for instant inspections. Screw off ...

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$74.59 - $74.59
$74.59
$74.59 - $74.59
$74.59
T-H Marine Straight Extra Long Thru-Hull Fitting For Hose, White

T-H Marine Straight Extra Long Thru-Hull Fitting For Hose, White

$17.99 - $17.99
$17.99
$17.99 - $17.99
$17.99
Item locally warehoused

High Quality UV and Chemical Resistant Virgin Polypro Sized to Fit All Marine Hose

$17.99 - $17.99
$17.99
$17.99 - $17.99
$17.99
Thru Hull 3/4 Straight White

Thru Hull 3/4 Straight White

$17.49 - $17.49
$17.49
$17.49 - $17.49
$17.49
Item locally warehoused

High Quality UV and Chemical Resistant Virgin Polypro Sized to Fit All Marine Hose

$17.49 - $17.49
$17.49
$17.49 - $17.49
$17.49
T-H Marine 90 Degree Thru-Hull Fitting For Hose

T-H Marine 90 Degree Thru-Hull Fitting For Hose

$24.19 - $24.19
$24.19
$24.19 - $24.19
$24.19
Item locally warehoused

High quality UV and chemical resistant virgin polypropelene.Features a finished head and a single pass around nut.

$24.19 - $24.19
$24.19
$24.19 - $24.19
$24.19
T-H Marine Straight Extra Long Thru-Hull Fitting For Hose, White

T-H Marine Straight Extra Long Thru-Hull Fitting For Hose, White

$23.79 - $23.79
$23.79
$23.79 - $23.79
$23.79
Item locally warehoused

High Quality UV and Chemical Resistant Virgin Polypro Sized to Fit All Marine Hose

$23.79 - $23.79
$23.79
$23.79 - $23.79
$23.79
T-H Marine Straight Thru-Hull Fitting For Hose, White

T-H Marine Straight Thru-Hull Fitting For Hose, White

$18.29 - $18.29
$18.29
$18.29 - $18.29
$18.29
Item locally warehoused

High Quality UV and Chemical Resistant Virgin Polypro Sized to Fit All Marine Hose

$18.29 - $18.29
$18.29
$18.29 - $18.29
$18.29
T-H Marine 90 Degree Specialty Thru-Hull Fitting With Spanner Head 3/4", Black

T-H Marine 90 Degree Specialty Thru-Hull Fitting With Spanner Head 3/4", Black

$24.49 - $24.49
$24.49
$24.49 - $24.49
$24.49
Item locally warehoused

High quality UV and chemical resistant virgin polypropelene.Features a finished head and a single pass around nut.

$24.49 - $24.49
$24.49
$24.49 - $24.49
$24.49
Attwood Thru Hull Connector For Hose, White, 90 Degree - 3/4"

Attwood Thru Hull Connector For Hose, White, 90 Degree - 3/4"

$23.19 - $23.19
$23.19
$23.19 - $23.19
$23.19
Item locally warehoused

Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows countersinkin...

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$23.19 - $23.19
$23.19
$23.19 - $23.19
$23.19
Attwood Thru Hull Connector For Hose, White - 1-1/2"

Attwood Thru Hull Connector For Hose, White - 1-1/2"

$24.99 - $24.99
$24.99
$24.99 - $24.99
$24.99
Item locally warehoused

Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows countersinkin...

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$24.99 - $24.99
$24.99
$24.99 - $24.99
$24.99
Attwood Thru Hull Connector For Hose, White - 1-1/8" to 1-1/4"

Attwood Thru Hull Connector For Hose, White - 1-1/8" to 1-1/4"

$24.39 - $24.39
$24.39
$24.39 - $24.39
$24.39
Item locally warehoused

Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows countersinkin...

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$24.39 - $24.39
$24.39
$24.39 - $24.39
$24.39
Attwood Thru Hull Connector For Hose, White - 3/4"

Attwood Thru Hull Connector For Hose, White - 3/4"

$16.29 - $16.29
$16.29
$16.29 - $16.29
$16.29
Item locally warehoused

Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows countersinkin...

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$16.29 - $16.29
$16.29
$16.29 - $16.29
$16.29
Attwood Thru Hull Connector For Hose, White - 3/4"

Attwood Thru Hull Connector For Hose, White - 3/4"

$36.39 - $36.39
$36.39
$36.39 - $36.39
$36.39
Item locally warehoused

Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows countersinkin...

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$36.39 - $36.39
$36.39
$36.39 - $36.39
$36.39
Johnson Pump 75035 3/4" 90° White Thru-Hull

Johnson Pump 75035 3/4" 90° White Thru-Hull

$28.29 - $28.29
$28.29
$28.29 - $28.29
$28.29
Item locally warehoused

Fittings are molded of tough acetal resin so they will not rust, corrode, discolor nor are they susceptible to electrolysis. White. Skin pack.

$28.29 - $28.29
$28.29
$28.29 - $28.29
$28.29
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$212.17 - $212.17
$212.17
$212.17 - $212.17
$212.17
Item locally warehoused

Precision molded in high strength glass-reinforced Marelon.Their strength, light weight, and complete freedom from corrosion and electrolysis make ...

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$212.17 - $212.17
$212.17
$212.17 - $212.17
$212.17
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$200.61 - $200.61
$200.61
$200.61 - $200.61
$200.61
Item locally warehoused

Precision molded in high strength glass-reinforced Marelon.Their strength, light weight, and complete freedom from corrosion and electrolysis make ...

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$200.61 - $200.61
$200.61
$200.61 - $200.61
$200.61
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$85.94 - $85.94
$85.94
$85.94 - $85.94
$85.94
Item locally warehoused

Precision molded in high strength glass-reinforced Marelon.Their strength, light weight, and complete freedom from corrosion and electrolysis make ...

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$85.94 - $85.94
$85.94
$85.94 - $85.94
$85.94
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$75.91 - $75.91
$75.91
$75.91 - $75.91
$75.91
Item locally warehoused

Precision molded in high strength glass-reinforced Marelon.Their strength, light weight, and complete freedom from corrosion and electrolysis make ...

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$75.91 - $75.91
$75.91
$75.91 - $75.91
$75.91
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$37.19 - $37.19
$37.19
$37.19 - $37.19
$37.19
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

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$37.19 - $37.19
$37.19
$37.19 - $37.19
$37.19
Forespar MF810 Marelon Water Strainer, 1-1/2"

Forespar MF810 Marelon Water Strainer, 1-1/2"

$293.80 - $293.80
$293.80
$293.80 - $293.80
$293.80
Item locally warehoused

Made of Marelon® and features an integral mounting bracket and clear polycarbonate lid for ready inspection. The stainless steel strainer basket ca...

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$293.80 - $293.80
$293.80
$293.80 - $293.80
$293.80
Forespar Marelon Scoop Strainer, White

Forespar Marelon Scoop Strainer, White

$60.18 - $60.18
$60.18
$60.18 - $60.18
$60.18
Item locally warehoused

High-strength, high speed, made of glass-reinforced non-corrosive Marelon®.Two piece construction allows for greater ease in installation.

$60.18 - $60.18
$60.18
$60.18 - $60.18
$60.18
Forespar Marelon Scoop Strainer, White

Forespar Marelon Scoop Strainer, White

$55.90 - $55.90
$55.90
$55.90 - $55.90
$55.90
Item locally warehoused

High-strength, high speed, made of glass-reinforced non-corrosive Marelon®.Two piece construction allows for greater ease in installation.

$55.90 - $55.90
$55.90
$55.90 - $55.90
$55.90
Forespar MF849 1-1/2" Marelon Flange Mounting PTFE Seacock

Forespar MF849 1-1/2" Marelon Flange Mounting PTFE Seacock

$250.78 - $250.78
$250.78
$250.78 - $250.78
$250.78
Item locally warehoused

Molded from lightweight, high-strength glass-reinforced Marelon™ composite, these flanged seacocks don't corrode, and are highly resistant to UV de...

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$250.78 - $250.78
$250.78
$250.78 - $250.78
$250.78
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$64.46 - $64.46
$64.46
$64.46 - $64.46
$64.46
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

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$64.46 - $64.46
$64.46
$64.46 - $64.46
$64.46
Forespar MF849 3/4" Marelon Flange Mounting PTFE Seacock

Forespar MF849 3/4" Marelon Flange Mounting PTFE Seacock

$113.17 - $113.17
$113.17
$113.17 - $113.17
$113.17
Item locally warehoused

Molded from lightweight, high-strength glass-reinforced Marelon™ composite, these flanged seacocks don't corrode, and are highly resistant to UV de...

View full details
$113.17 - $113.17
$113.17
$113.17 - $113.17
$113.17
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$42.97 - $42.97
$42.97
$42.97 - $42.97
$42.97
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$42.97 - $42.97
$42.97
$42.97 - $42.97
$42.97
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$34.33 - $34.33
$34.33
$34.33 - $34.33
$34.33
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$34.33 - $34.33
$34.33
$34.33 - $34.33
$34.33
Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

Forespar CF253 Marelon Hose Tailpipe Mushroom Head Thru Hull w/Nut, White

$30.04 - $30.04
$30.04
$30.04 - $30.04
$30.04
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

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$30.04 - $30.04
$30.04
$30.04 - $30.04
$30.04
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$68.73 - $68.73
$68.73
$68.73 - $68.73
$68.73
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$68.73 - $68.73
$68.73
$68.73 - $68.73
$68.73
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$40.15 - $40.15
$40.15
$40.15 - $40.15
$40.15
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$40.15 - $40.15
$40.15
$40.15 - $40.15
$40.15
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$34.33 - $34.33
$34.33
$34.33 - $34.33
$34.33
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$34.33 - $34.33
$34.33
$34.33 - $34.33
$34.33
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$30.04 - $30.04
$30.04
$30.04 - $30.04
$30.04
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$30.04 - $30.04
$30.04
$30.04 - $30.04
$30.04
Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

Forespar CF251 Marelon Full Threaded Mushroom Head Thru Hull w/Nut, White

$28.68 - $28.68
$28.68
$28.68 - $28.68
$28.68
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$28.68 - $28.68
$28.68
$28.68 - $28.68
$28.68
Forespar CF250 Marelon Full Threaded Flush Head Thru Hull w/Nut, White

Forespar CF250 Marelon Full Threaded Flush Head Thru Hull w/Nut, White

$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53
Item locally warehoused

Made from high strength glass-reinforced Marelon. Ideal for use above or below the waterline. Must be installed with proper bedding compound. Recom...

View full details
$51.53 - $51.53
$51.53
$51.53 - $51.53
$51.53