Thanks Kendal and Alan. For some reason I didn't get notified of your replies.
It's a Steve Haywood boat, built 2005. There are no heated docks around unfortunately (that can fit me in, and that I can get to with the winter stoppages). So, I'd much rather wait if it won't cause too much of a problem! And yes, i'll be in a marina and hooked up.
Notes from the survey below:
The side plating measured between 5.8mm and 6.0mm. These readings are satisfactory. Pitting was found on the side plating mostly at 0.75mm in a light rash in frequency. Deeper pitting up to 3.0mm deep was occasionally found in a light rash aft by the stern gear. This is a defect often found caused by the more noble metals of the stern gear. Remove the blacking coatings from the after sections of the swim plating say 45cm extending forwards of the stern post and locally plug weld pits at or over 1.5mm deep.
Sacrificial hull anodes were fitted paired forward and aft found un-wasted and well attached.
The bottom plate was also measured in 20 random and selected places and was between 9.7mm and 9.9mm in the areas measured. These readings were indicative of the plate being originally 10mm nominal thickness. Pitting was found on the bottom plating at 1.5mm in a moderate rash in frequency. The bottom plate had not been blacked in the past which unfortunately is common practice. Consider preparing and painting the bottom plate.
The uxter plate had been fabricated from 10.0mm mild steel plate. Thickness measurements were taken at 9.8mm. Pitting was found on the uxter plating at 0.5mm in a light rash in frequency. The sacrificial chine or wear edges (the projection of the bottom plates from the hull sides, which protect the joint welds) were inspected and were found to be offering adequate protection.
Recommendations.
* The immersed plating should be thoroughly blacked after careful preparations especially along the waterline.
* Consider preparing and painting the bottom plate.
* Remove the blacking coatings from the after sections of the swim plating say 45cm extending forwards of the stern post and locally plug weld pits at or over 1.5mm deep.
Thanks for any further thoughts...!