Without looking at a chart but looking at the cove, follow the angle of the beach and land at the back of the cove with your eye and you can see how that line will continue beneath the water, making the end of the cove near the beach the most shallow and deeper at the entrance. The pronounced canyon leading directly to the cove at the back should alert you that the cove is vulnerable to winds coming out of the canyon (If you have done your weather homework, you’ll know about the local Santa Ana winds and will be aware of the conditions that bring them on, as well as be able to get out quickly when you see these conditions, before the winds hit – They usually are in the 50 – 70 knot range!).

If you look at the eastern cliff, you can see how the bottom will be flat until it arrives at the cliff. Because it’s a vertical cliff, beware of boulders that have fallen, nearby – Sure enough, that’s precisely what the bottom looks like on that side! On the west side, the steep ridge shows that the bottom will continue from the center to that ridge steeply, so it’s possible to sail fairly close to it, again looking out for boulders. This gives the transverse (side-to-side) profile of the cove a general tilt from shallowest on the ridge side to deepest on the cliff side.

There are a couple of things the reef tells us: It’s great protection to anchor behind; there is a particular danger of outlying rocks to run aground on; the reef collects sand running out from the cove, so the cove will have a sandy bottom; surge in the cove will be swiftest around the edge of the reef but that’s where it’s deepest, so the cove isn’t going to normally be very surgey.

Looking at the angle of the ground running in a particular direction towards the sea or parallel with it usually gives an excellent idea of the contours of the sea floor. I’ve just used a complicated topography to show how you can use this technique in almost any location. This technique will usually give you an excellent guide to the general features of particular locations and that is invaluable, visually, in seeking a safe, comfortable anchorage, seeking a path around a strong costal current or in general costal navigation.

There are a couple of warnings I must give, though – Reefs are often random and unexpected: Wear is vastly different above, versus below water and pinnacles can result in odd places. In addition, coral grows and wrecks happen. Keeping your charts up to date with costal updates and planning your costal navigation with your charts is imperative for your safety.

There is a corollary to this technique that is also invaluable: If you see something notable in one place on a coast, you’re likely to see it nearby, as well. This last spring, I delivered a boat from Mazatlan to Los Angeles and while at Turtle Bay, heard a tale of a buddy boat to the boat I was helping anchor: They had seen pinnacles offshore up to twelve miles. Their buddy boat thought those pinnacles were a one-time hazard and so sailed six miles off shore, where they hit one, taking on water faster than their pumps could handle, through the bilge. They headed inshore, to ground on the beach but hit another, three miles offshore, that instantly sank the boat. By that time, they were towing their dinghy and had it loaded with emergency provisions and were in the cockpit, so they lived. The buddy boat, more carefully, sailed inshore and rescued them and deposited their friends at Turtle Bay the day before I stopped by.

Sadly, in navigation, so many live for the moment and cut corners – These people lost their cruising boat and everything on it because they didn’t take Mother Nature seriously enough. The people I talked to had repeatedly warned their doomed friends but to no avail. Please take the time and effort to equip your boat well, take reasonable precautions, do things properly and always, always keep a proper watch. Oh, and if you’re cruising Baja, stay at least twelve miles out – I sailed past two uncharted breaking pinnacles that far out, this last trip! Eek!