Lowes & home depot sells Black Restaurant kitchen rubber mats. About $26 a 3'x3' section. They snap together on edges and can be cut with heavy sissors. They,re about 1/2" thick and are made in a honeycomb grid which lets water pass thru. Absolute insulation from hot/cold floors and stop you from slipping on icey floors. Simple to take in and out to clean boat floor when needed. Heavy enough that they don,t move. I,ve used them in all my boats for years and best bang for the buck I,ve ever found.