Sailors would use different markers to find a safe route through these treacherous waters. The markers could be islets, skerries, buildings and so on. Where the land is as flat as around Slettnes there would also be special manmade installations such as stone or wooden beacons. One such beacon stood until recently 1km east of Slettnes and was a 10-12m tall triangular wooden structure. This warning sign was locally called "the cross".