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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

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

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

$32.89 - $32.89
$32.89
$32.89 - $32.89
$32.89
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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$32.89 - $32.89
$32.89
$32.89 - $32.89
$32.89
Forespar CF250 Marelon Full Threaded Flush Head Thru Hull w/Nut, White

Forespar CF250 Marelon Full Threaded Flush 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...

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$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

$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...

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$28.68 - $28.68
$28.68
$28.68 - $28.68
$28.68
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$323.89 - $323.89
$323.89
$323.89 - $323.89
$323.89
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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$323.89 - $323.89
$323.89
$323.89 - $323.89
$323.89
Forespar MF850 Marelon PTFE Ball Valve

Forespar MF850 Marelon PTFE Ball Valve

$262.24 - $262.24
$262.24
$262.24 - $262.24
$262.24
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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$262.24 - $262.24
$262.24
$262.24 - $262.24
$262.24
Forespar Marelube Valve Lubricant, 4 oz.

Forespar Marelube Valve Lubricant, 4 oz.

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

A synthetic advanced lubrication formula designed to keep valve seals and balls working smoothly in marine plumbing systems.It is a clear, non-stai...

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$28.68 - $28.68
$28.68
$28.68 - $28.68
$28.68
Seachoice Double-Ended 3/4" x 3/4" Thru Hull Connector For Hose

Seachoice Double-Ended 3/4" x 3/4" Thru Hull Connector For Hose

$20.59 - $20.59
$20.59
$20.59 - $20.59
$20.59
Item locally warehoused

Designed to provide watertight transition through tanks or bulk heads. Hose ID 3/4". Length: 4-3/4"

$20.59 - $20.59
$20.59
$20.59 - $20.59
$20.59
Seachoice Extra Long Thru-Hull Fitting w/ Broad Flange For 1-1/8 In. ID Hose, 3 In. Long Thread

Seachoice Extra Long Thru-Hull Fitting w/ Broad Flange For 1-1/8 In. ID Hose, 3 In. Long Thread

$17.89 - $17.89
$17.89
$17.89 - $17.89
$17.89
Item locally warehoused

The Seachoice 18181 Extra Long Thru-Hull Fitting With Broad Flange is designed for installation in thick transoms or side walls, and for applicatio...

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$17.89 - $17.89
$17.89
$17.89 - $17.89
$17.89
Seachoice Plastic Thru-Hull With Broad Flange

Seachoice Plastic Thru-Hull With Broad Flange

$15.69 - $15.69
$15.69
$15.69 - $15.69
$15.69
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$15.69 - $15.69
$15.69
$15.69 - $15.69
$15.69
Seachoice Polypropylene Extra Long Thru-Hull Connector for 3/4 in. ID Hose, White Finish

Seachoice Polypropylene Extra Long Thru-Hull Connector for 3/4 in. ID Hose, White Finish

$13.49 - $13.49
$13.49
$13.49 - $13.49
$13.49
Item locally warehoused

Providing anglers with a reliable connection above the waterline, this high impact plastic thru-hull connector is critical to safe and dependable o...

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$13.49 - $13.49
$13.49
$13.49 - $13.49
$13.49
3/4" Black Plastic Thru-Hull w/Broad Flange

3/4" Black Plastic Thru-Hull w/Broad Flange

$10.69 - $10.69
$10.69
$10.69 - $10.69
$10.69
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$10.69 - $10.69
$10.69
$10.69 - $10.69
$10.69
Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/8 In. ID Hose, 1-1/8 In. Max Hull

Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/8 In. ID Hose, 1-1/8 In. Max Hull

$23.39 - $23.39
$23.39
$23.39 - $23.39
$23.39
Item locally warehoused

Seachoice 90 Degree Thru-Hull Connectors are made of durable, high-impact plastic to withstand the rigors of marine environments. They are designed...

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$23.39 - $23.39
$23.39
$23.39 - $23.39
$23.39
Seachoice 90-Degree Angled Thru-Hull Connector, White Finish, 0.75 in.

Seachoice 90-Degree Angled Thru-Hull Connector, White Finish, 0.75 in.

$12.89 - $12.89
$12.89
$12.89 - $12.89
$12.89
Item locally warehoused

Providing anglers with a reliable connection above the waterline, this high impact plastic thru-hull connector is critical to safe and dependable o...

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$12.89 - $12.89
$12.89
$12.89 - $12.89
$12.89
Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/2 in. ID Hose, 1-3/8 in. Max Hull

Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/2 in. ID Hose, 1-3/8 in. Max Hull

$26.69 - $26.69
$26.69
$26.69 - $26.69
$26.69
Item locally warehoused

Seachoice 90 Degree Thru-Hull Connectors are made of durable, high-impact plastic to withstand the rigors of marine environments. They are designed...

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$26.69 - $26.69
$26.69
$26.69 - $26.69
$26.69
Seachoice Thru-Hull Connector w/ Broad Flange, White Finish, 1.5 In.

Seachoice Thru-Hull Connector w/ Broad Flange, White Finish, 1.5 In.

$20.59 - $20.59
$20.59
$20.59 - $20.59
$20.59
Item locally warehoused

Providing anglers with a reliable connection above the waterline, this high impact plastic thru-hull connector with broad flange is critical to saf...

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$20.59 - $20.59
$20.59
$20.59 - $20.59
$20.59
Seachoice 90 Degree Plastic Thru-Hull, White

Seachoice 90 Degree Plastic Thru-Hull, White

$20.69 - $20.69
$20.69
$20.69 - $20.69
$20.69
Item locally warehoused

1-1/8" 90 Degree White Plastic Thru Hull

$20.69 - $20.69
$20.69
$20.69 - $20.69
$20.69
Seachoice 18091 Thru-Hull Connector w/ Broad Flange, White Finish, 1.125 In.

Seachoice 18091 Thru-Hull Connector w/ Broad Flange, White Finish, 1.125 In.

$14.19 - $14.19
$14.19
$14.19 - $14.19
$14.19
Item locally warehoused

Providing anglers with a reliable connection above the waterline, this high impact plastic thru-hull connector with broad flange is critical to saf...

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$14.19 - $14.19
$14.19
$14.19 - $14.19
$14.19
Seachoice 90 Degree Stainless Steel Covered Thru-Hull

Seachoice 90 Degree Stainless Steel Covered Thru-Hull

$50.79 - $50.79
$50.79
$50.79 - $50.79
$50.79
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$50.79 - $50.79
$50.79
$50.79 - $50.79
$50.79
1-1/8" White Plastic Thru-Hull w/Broad Flange

1-1/8" White Plastic Thru-Hull w/Broad Flange

$12.59 - $12.59
$12.59
$12.59 - $12.59
$12.59
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$12.59 - $12.59
$12.59
$12.59 - $12.59
$12.59
Seachoice 90 Degree Stainless Steel Covered Thru-Hull

Seachoice 90 Degree Stainless Steel Covered Thru-Hull

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

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$40.29 - $40.29
$40.29
$40.29 - $40.29
$40.29
Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/8 In. ID Hose, 1-3/8 In. Max Hull

Seachoice 90-Degree Thru-Hull Connector, Fits 1-1/8 In. ID Hose, 1-3/8 In. Max Hull

$37.29 - $37.29
$37.29
$37.29 - $37.29
$37.29
Item locally warehoused

Seachoice 90 Degree Thru-Hull Connectors are made of polypropylene and glass fiber for strength. The stainless-steel flange offers excellent corros...

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$37.29 - $37.29
$37.29
$37.29 - $37.29
$37.29
Seachoice 18061 90-Degree Thru Hull Fitting, Fits 3/4 In. ID Hose, 7/8 In. Max. Hull

Seachoice 18061 90-Degree Thru Hull Fitting, Fits 3/4 In. ID Hose, 7/8 In. Max. Hull

$13.89 - $13.89
$13.89
$13.89 - $13.89
$13.89
Item locally warehoused

The Seachoice 90° Thru-Hull Fitting is designed for places where the hose is difficult to route. It accommodates 3/4 inch ID hose, and is ideal for...

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$13.89 - $13.89
$13.89
$13.89 - $13.89
$13.89
Seachoice 90 Degree Stainless Steel Covered Thru-Hull

Seachoice 90 Degree Stainless Steel Covered Thru-Hull

$27.53 - $27.53
$27.53
$27.53 - $27.53
$27.53
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$27.53 - $27.53
$27.53
$27.53 - $27.53
$27.53
Seachoice 90-Degree Thru-Hull Connector, Fits 3/4 In. ID Hose, 1-3/8 In. Max Hull, White

Seachoice 90-Degree Thru-Hull Connector, Fits 3/4 In. ID Hose, 1-3/8 In. Max Hull, White

$21.39 - $21.39
$21.39
$21.39 - $21.39
$21.39
Item locally warehoused

Seachoice 90 Degree Thru-Hull Connectors are made of polypropylene and glass fiber for strength. The stainless-steel flange offers excellent corros...

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$21.39 - $21.39
$21.39
$21.39 - $21.39
$21.39
3/4" White Plastic Thru-Hull w/Broad Flange

3/4" White Plastic Thru-Hull w/Broad Flange

$7.09 - $7.09
$7.09
$7.09 - $7.09
$7.09
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$7.09 - $7.09
$7.09
$7.09 - $7.09
$7.09
Seachoice 90 Degree Stainless Steel Covered Thru-Hull

Seachoice 90 Degree Stainless Steel Covered Thru-Hull

$26.09 - $26.09
$26.09
$26.09 - $26.09
$26.09
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$26.09 - $26.09
$26.09
$26.09 - $26.09
$26.09
5/8" White Plastic Thru-Hull w/Broad Flange

5/8" White Plastic Thru-Hull w/Broad Flange

$7.69 - $7.69
$7.69
$7.69 - $7.69
$7.69
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$7.69 - $7.69
$7.69
$7.69 - $7.69
$7.69
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$43.28 - $43.28
$43.28
$43.28 - $43.28
$43.28
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$43.28 - $43.28
$43.28
$43.28 - $43.28
$43.28
5/8" White Plastic Thru-Hull w/Broad Flange

5/8" White Plastic Thru-Hull w/Broad Flange

$5.83 - $5.83
$5.83
$5.83 - $5.83
$5.83
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$5.83 - $5.83
$5.83
$5.83 - $5.83
$5.83
1/2" White Plastic Thru-Hull w/Broad Flange

1/2" White Plastic Thru-Hull w/Broad Flange

$10.19 - $10.19
$10.19
$10.19 - $10.19
$10.19
Item locally warehoused

Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft". Not recommended for use below the waterline.

$10.19 - $10.19
$10.19
$10.19 - $10.19
$10.19
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$33.69 - $33.69
$33.69
$33.69 - $33.69
$33.69
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$33.69 - $33.69
$33.69
$33.69 - $33.69
$33.69
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$28.99 - $28.99
$28.99
$28.99 - $28.99
$28.99
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$28.99 - $28.99
$28.99
$28.99 - $28.99
$28.99
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$25.89 - $25.89
$25.89
$25.89 - $25.89
$25.89
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$25.89 - $25.89
$25.89
$25.89 - $25.89
$25.89
Seachoice Chrome Plated Plastic Thru-Hull

Seachoice Chrome Plated Plastic Thru-Hull

$21.99 - $21.99
$21.99
$21.99 - $21.99
$21.99
Item locally warehoused

Use in place of stainless steel thru-hulls.Not recommended for use below the waterline.

$21.99 - $21.99
$21.99
$21.99 - $21.99
$21.99
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$25.89 - $25.89
$25.89
$25.89 - $25.89
$25.89
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$25.89 - $25.89
$25.89
$25.89 - $25.89
$25.89
Seachoice Chrome Plated Plastic Thru-Hull

Seachoice Chrome Plated Plastic Thru-Hull

$15.89 - $15.89
$15.89
$15.89 - $15.89
$15.89
Item locally warehoused

Use in place of stainless steel thru-hulls.Not recommended for use below the waterline.

$15.89 - $15.89
$15.89
$15.89 - $15.89
$15.89
Seachoice Stainless Steel Covered Thru-Hull

Seachoice Stainless Steel Covered Thru-Hull

$20.44 - $20.44
$20.44
$20.44 - $20.44
$20.44
Item locally warehoused

Molded from polypropylene with glass fiber for strength.Not recommended for use below the waterline.

$20.44 - $20.44
$20.44
$20.44 - $20.44
$20.44
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$105.04 - $105.04
$105.04
$105.04 - $105.04
$105.04
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

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$105.04 - $105.04
$105.04
$105.04 - $105.04
$105.04
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$81.36 - $81.36
$81.36
$81.36 - $81.36
$81.36
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

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$81.36 - $81.36
$81.36
$81.36 - $81.36
$81.36
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$48.81 - $48.81
$48.81
$48.81 - $48.81
$48.81
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

View full details
$48.81 - $48.81
$48.81
$48.81 - $48.81
$48.81
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$34.10 - $34.10
$34.10
$34.10 - $34.10
$34.10
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

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$34.10 - $34.10
$34.10
$34.10 - $34.10
$34.10
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$31.08 - $31.08
$31.08
$31.08 - $31.08
$31.08
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

View full details
$31.08 - $31.08
$31.08
$31.08 - $31.08
$31.08
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$491.09 - $491.09
$491.09
$491.09 - $491.09
$491.09
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

View full details
$491.09 - $491.09
$491.09
$491.09 - $491.09
$491.09
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$341.69 - $341.69
$341.69
$341.69 - $341.69
$341.69
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

View full details
$341.69 - $341.69
$341.69
$341.69 - $341.69
$341.69
Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

Groco TH Bronze Standard Length Thru-Hull With Nut, NPS Thread

$158.34 - $158.34
$158.34
$158.34 - $158.34
$158.34
Item locally warehoused

Should have threaded portion cut to proper length considering hull and butt block thickness. Consider thread depth when using a seacock. Sealant is...

View full details
$158.34 - $158.34
$158.34
$158.34 - $158.34
$158.34
Attwood Thru Hull Stainless Steel 1-1/2" For Hose

Attwood Thru Hull Stainless Steel 1-1/2" For Hose

$149.59 - $149.59
$149.59
$149.59 - $149.59
$149.59
Item locally warehoused

Cast from 316 stainless steel. A channel under the flange holds a bead of sealant. All models have wrench flats or an end notch. Designed for insta...

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$149.59 - $149.59
$149.59
$149.59 - $149.59
$149.59
Attwood Thru Hull Stainless Steel 1-1/8" For Hose

Attwood Thru Hull Stainless Steel 1-1/8" For Hose

$102.69 - $102.69
$102.69
$102.69 - $102.69
$102.69
Item locally warehoused

Cast from 316 stainless steel. A channel under the flange holds a bead of sealant. All models have wrench flats or an end notch. Designed for insta...

View full details
$102.69 - $102.69
$102.69
$102.69 - $102.69
$102.69
Attwood Thru Hull Stainless Steel 1" For Hose

Attwood Thru Hull Stainless Steel 1" For Hose

$88.29 - $88.29
$88.29
$88.29 - $88.29
$88.29
Item locally warehoused

Cast from 316 stainless steel. A channel under the flange holds a bead of sealant. All models have wrench flats or an end notch. Designed for insta...

View full details
$88.29 - $88.29
$88.29
$88.29 - $88.29
$88.29