Simple Encounter tables for Coastal Terrain for Low (1-3), Mid (4-10) and High (11+) levels. Support for Volo's Guide to Monsters and Mordenkainen's Tome of Foes.
Extra tables for Coastal Locations, beasts, humanoids, elementals and kobolds
Tables use 2-20 range designed with unusual and dangerous encounters occurring less often using 1d12+1d8 or 2d10. Or use 1d20 and use 1s to roll twice or pick a result.