Incorporate a concept of route difficulty, matched to skill level of the kayaker, based on e.g. british canoeing criteria

[NathanSkene]

Beginners would only be shown routes that have no wild without protection.

Advanced kayakers would be shown routes with high beufort scale winds, serious tides etc

Geographic features along the route would increase difficulty (e.g. Hells Mouth near Bull Bay in Anglesey, a canyon angled along the prevailing wind, which blasts the wind at kayakers crossing it)