Thru-Hull Fittings

  1. Groco Combo Thru-Hull Fitting with Nut

    $16.79 - $792.99
    1
  2. Forespar 253 Series Marelon Mushroom Head Thru-Hull Fitting

    $15.96 - $35.96
    0
  3. Groco RSC Series Round Hull Strainer

    $60.99 - $418.99
    0
  4. Groco Bronze Scoop Thru-Hull Strainer with Nut

    $24.99 - $171.99
    0
  5. Groco HTH Series Hose Barb Thru-Hull Fitting

    $17.15 - $79.99
    1
  6. Forespar CF 251 Series Marelon Mushroom Head Thru-Hull Fitting

    $15.96 - $38.36
    0
  7. 19% off

    Whitecap Stainless Steel Thru-Hull with Barb

    $24.99 - $73.99
    $22.49 - $73.99
    0
  8. Groco SC Series Bronze Clam Shell Style Hull Strainer

    $29.99 - $299.99
    0
  9. Groco Combo XL Thru-Hull

    $26.99 - $81.99
    0
  10. Forespar CF 254S Marelon Flush Head Deck Drain/Thru Hull with Screen

    $18.36 - $40.76
    0
  11. Andersen Automatic Bailer

    $77.99 - $140.99
    0
  12. 46% off

    Whitecap Plastic Mushroom Head Thru-Hull Fitting with SS Flange

    $11.30 - $29.99
    $9.15 - $29.99
    0
  13. SHURflo Livewell Fill Valve - 330-021

    $36.99
    1
  14. 39% off

    Whitecap 90 deg. Thru-Hull with Barb

    $5.49 - $6.71
    $3.38 - $6.71
    1
  15. Forespar CF 250 Series Marelon Flush Head Thru-Hull Fitting

    $14.36 - $28.76
    0
  16. 16% off

    Whitecap 316 Stainless Steel Thru Hull

    $41.99 - $107.99
    $41.99 - $91.99
    0
  17. Groco FTH Series Bronze Flush Mount Thru-Hull Fitting

    $18.66 - $54.99
    0
  18. Forespar Scoop Strainer

    $31.16 - $33.56
    0
  19. 42% off

    Groco TH Series Thru-Hull Lock Nut

    $7.20 - $317.99
    $7.20 - $317.99
    0
  20. Whitecap Long Neck Thru Hull - 6554

    $72.99
    0
  21. Whitecap 90 deg SS Thru-Hull with Barb - 6579

    $57.99
    0
  22. Groco ASC Series Slotted Hull Strainer

    $151.99 - $1,054.99
    0
  23. Attwood Plastic Mushroom Head Thru-Hull Fitting

    $5.03 - $9.07
    0
  24. Groco HTHC Series 90 deg. Hose Thru-Hull Fitting

    $42.99 - $151.99
  25. 48% off

    Whitecap Straight Thru-Hull with Barb

    $4.99 - $6.22
    $2.60 - $5.99
    0
  26. 19% off

    Rule Acetal Resin Mushroom Head Thru-Hull Fitting - 61

    $11.21
    $9.08
    0
  27. Groco HSTH Series Combo High Speed Pickup Thru-Hull Fitting with Nut

    $17.90 - $1,021.70
  28. Whitecap Nylon Thru Hull with SS Flange Cover - S-3813

    $25.99
    0
  29. Rule Acetal Resin Mushroom Head Thru-Hull Fitting - 1 1/8" - 60

    $12.82
    0
  30. Vetus Stainless Steel Water Scoop

    $28.99 - $81.99
  31. T-H Marine Straight Thru-Hull Fittings

    $5.35 - $15.26
    0
  32. T-H Marine 3/4" 90 deg. Thru-Hull Fittings

    $6.88 - $9.55
    0
  33. Groco Combo HSTHXL Series High Speed XL Pickup Thru-Hull Fitting with Nut

    $31.99 - $106.25
  34. 15% off

    Apollo Conbraco 65-Series Bronze Thru-Hull Flanged Retainer Nut

    $2.53 - $20.00
    $2.15 - $18.00
    0
  35. Groco APHS Series Bronze Hull Scoop Strainer with Access Door

    $176.99 - $384.99

About Thru-Hull Fittings

Thru Hull Fittings & Tools

Defender Marine offers a full line of thru hull fittings fabricated in a variety of materials. From ½ inch up to 5 inches, our boat thru hulls are the key to successfully rigging any type of intake/discharge pump above or below the waterline. Washdowns, circulating pumps and even saltwater cooled engines depend on the correct size boat thru hull, strainer, valve, and reinforced hose system. Strainers in several shapes, as well as tools to facilitate thru hull installation, are also available at Defender Marine.

What's the best way to install a marine thru hull fitting?

Remember that old adage - slow and steady wins the race? Well, there is no location on a boat to be more careful and slower than installing thru hulls below the waterline. First things first - haul your boat and let it settle, especially if it has a wooden hull. Next, get all of your details straight before you dig out that hole saw! Match pipe thread, determine if your job needs a seacock, fabricate and fit a backing plate and confirm that your metals are compatible to avoid electrolysis. Finally, make certain that all adhesives and sealants have cured prior to going back to the water!

The trials and tribulations of boat thru hulls and strainers.

Isn't it great when an overheated pump turns out to be a clogged or blocked strainer instead of an issue that requires a mechanic and all of his tools? Marine thru hull systems offers several layers of protection for your intake and the expensive mechanical equipment beyond. Strainers and thru hulls with strainer systems from Defender come in several shapes sizes and keep large debris from entering through the hull.

This thru hull fitting is made of what?

Defender offers thru hull fittings made of just about anything. There are several items to consider when choosing your boat thru hull. The most important is the strength of your fitting; in some applications, a seacock or backing plate may strengthen your project. The next is electrolysis. When it comes to boats, electrolysis is part of life, but boat thru hull fittings are normally located under the waterline where metals react more severely. Be certain metals are compatible or use plastic or Marelon thru hull fittings - these are guaranteed not to pit!