Home/Best Blogs/Boating Safety – Know These Dangerous Rock Symbols! Best BlogsCruisingSkipperTipsUSA Boating Safety – Know These Dangerous Rock Symbols! 18 January 2017 Less than a minute Facebook Twitter LinkedIn Pinterest Reddit WhatsApp Share via Email Print How are dangerous rocks displayed on your nautical or electronic charts? Protect your sailboat hull, keel, rudder or propeller from costly damage. Watch this sailing video to learn to sail with more confidence worldwide! Visit http://www.skippertips.com for more boating safety and sailing tips like these.