Wood Moisture Meter
JR Overseas
  • Wood Moisture Meter
  • Marine Moisture Meter

Wood and Composite Moisture Meter

The GRP-33 wood moisture meter detects water content in wood and fiberglass. This analog meter indicates moisture levels in fiberglass up to 3% and wood up to 30%. Use on fiberglass boats to detect osmosis before gel coat blistering occurs. Check hull dryness before painting, or use to find and trace leaks on boats of all kinds.

Moisture meters are used by surveyors, boatyards, yacht brokers, boat painters, yacht designers, and repair specialists. The GRP 33's non destructive detection system ideally suited for marine surveying, appraisal, and damage inspection. Move the sensing pad across the surface for readings.

Meter comes in a soft sided compartmentalized instrument case. Calibration may be checked quickly with the provided test block and may be reset in 2 minutes.

IN STOCK - Available for pickup  
$351.56 / ea
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Tech Spec Product Info User Generated Content


  • Detect Osmosis before gel coat blistering becomes a visual reality.
  • Monitor hull dryness for repairs and painting.
  • Identify and trace leaks.
  • Uses non-destructive, capacitance method, measuring electronically up to 1 inch deep.
  • Accurately provides readings on structures subject to salt, brackish and fresh water.
  • Refers to a quantitative scale for fiberglass and a scale range of up to 30% moisture for wood.
  • Uses a common 9v Battery as its long lasting power source.
  • Recalibration may be accomplished precisely and with ease using the furnished acrylic calibration block and copper panel.
  • Two Year Limited Warranty.


BRAND: JR Overseas
Type: Moisture Meter
4.7 3

Perfect tool for my work


great for checking the moisture content of a fiberglass hull before repairs are completed so you dont trap water in the laminate. No need to drill access holes

Fiberglass Dave

Delray Beach, Florida


lets me sleep nights


We had strange looking spider cracks in our newly painted hull. We do not have a core. We thought out boat was failing when we asked the fiberglass repair person at our marina. We bought the meter and checked our hull against all the other hulls in the marina and found ours was somewhat in the middle of moisture. The meter was complete as it gave us information on how to use, etc. We are now using it to monitor our newly repaired deck, to stay on top of moisture leakage. We sleep much better at night.


Long Island Sound, CT side


Check for leaks and save your core


A moisture meter is a great preventative and diagnostic tool. Leaks can develop around deck fittings at any time, at any location. Most boats today have a core in the deck and often in the hull. Most have balsa core that is vulnerable to water damage. If deck fittings aren't rebedded from time to time they can allow water to find a way to the core. If left uncorrected many $$$ worth of damage can result. Proper use of a moisture meter can detect such leaks early on and save lots of grief.


Long Island


Wood and Composite Moisture Meter



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