Some Mirror sailors like to have non-slip foam padding (e.g. Pro Grip) on the gunwales were the helm and crew sit. Widely available (in the UK at least), in different colours. Just Google 'Pro Grip sailing' to find a source.
- Round the corners so they don't get caught by clothing and ropes.
- Use a hairdryer to heat - it softens and makes it easier to take the gunwale shape.
- Its self adhesive and the hairdryer also warms the glue and makes it hold better.
- Use tape as you apply just to hold it tight in place until the adhesive has cured.
- It might take a couple of you to do a longer length.