The easiest way to check if your hull has any unfair areas,  it to have sunlight or strong artificial light shining from one end as you look along the hull either with or against the light.   If you really want to check the fairness, then the best time is at night.    Shine your torch along the hull and you will soon see all the imperfections in the surface.   Use this technique frequently during the final fairing process.  

   At this stage, you can expect your hull to show some imperfections and these can be removed during the final fairing operation.   You have to decide the standard of finish you are prepared to accept.   Set your standards as high as possible.   Work towards this goal and you will end with a hull you can be proud of.   The resale value of your boat is important and the better the finish the higher the value.

FINISHING THE HULL

If your hull has been carefully laminated and will not require too much finishing, you will be a lot closer to achieving a good looking boat than a sloppy builder and you will avoid a lot of back breaking hand sanding. 

   The first process in finishing a hull, is to sand the surface with a disc sander running at not more that 4000 RPM.   Use a soft pad (Ferro type) equipped with 30 to 40 grit open coat floor sanding type discs.   The soft pad will prevent you from digging holes or causing other imperfections as you sand the hull.   After you have sanded the outer layer of the mat, you must decide whether you need a professional plasterer to apply your screeding material.   If your hull is unfair and has many humps and hollows, you would be best advised to have a local tradesman screed your hull with resin putty “bog”.