Rips and Ocean Swimmers

If you are neither a good swimmer nor an experienced ocean swimmer, or if you don’t swim with someone who is, swim between the flags on a patrolled beach, and don’t swim alone.

No swimmer ever conquers the ocean. The sea requires the utmost respect from all those who submit themselves to it. The ocean is never trying to kill you. But if you fail to respect it, you can die there.

Standing on an ocean shore estimating how far it would be to swim to some identified point offshore, frequently results in under-estimation.

Standing on an ocean shore assessing wave size and power and how rough the water is offshore, frequently results in under-estimation.

Warning: I wrote this post with ocean swimmers in mind and because I wanted to record in one place my thoughts about rips. Others are unlikely to find this post interesting.

Ocean water moves around a lot, on scales ranging from global to local. The photos and observations below are about ocean currents close to shore as they affect ocean swimmers.

Swell direction, breaking waves, tides, wind and gravity can cause small but powerful localised currents within and extending beyond the surf zone. Ocean swimmers have an interest in understanding these currents which flow from the shallows out to sea beyond the shorebreak, either directly or at an angle. Such currents, known as rips, can be a metre or so wide, and they can flow quite slowly and extend only a short distance from shore. Sometimes they can be many tens of metres wide and flow away from shore at a speed which it is not possible to swim against. Sometimes they may extend many hundreds of metres beyond shore and connect to strong tidal currents with potential to take a swimmer to the next postcode. A swimmer in a rip who takes no active steps to leave the current will typically be carried out to deeper water beyond the shorebreak where the rip will fade and end.

Whether or not a particular rip poses a threat to the safety of a particular swimmer in a particular set of conditions depends on a lot of factors: the skill and experience level of the swimmer, the level of detail of the swimmer’s knowledge of the beach where the rip is located, the size, location, direction and strength of the rip, the size and power of the swell, the direction from which the swell has come relative to the direction the beach faces, the contours of the seabed in the vicinity, the general gradient of the seabed in the area, the nature of any reefs or other relief features beneath the water, the direction and strength of the wind and the surface conditions they are creating, the presence or absence of gutters and sandbars and their distance from shore, whether the beach is long and straight or a bay bookended with points or promontories, the tidal range on the day and whether the tide is ebbing, flowing or in the slack water period (if any).

Some rips are highly transient and can appear and disappear in seconds or minutes. These typically occur at beaches with sandy seabeds. Others flow like rivers following permanent rocky channels on the seabed whenever the surf is up and water washed ashore above its natural level heads back out to sea via the nearest line of least resistance. Some rips operate only when a big set (of waves) has come through, and others operate in very small surf.

Importantly, rips are often easier to see from a vantage point on the shore than they are while swimming. But some rips can be invisible from the shore, especially in rough surface conditions such as occur in strong winds with a lot of breaking waves and chop. The photos below illustrate a variety of visible rips at ocean beaches on the west coast of Victoria. The comments under the photos point out some of the tell-tale signs of visible rips.

It is highly instructive as an exercise or when you are planning a swim, to sit on the dunes and closely observe the behaviour of the water in and near the surf zone. This is especially so if you are unfamiliar with that beach. If you watch for say 15 minutes you will see transient currents and recurring patterns. You will begin to understand that the water is telling you a lot more than you learned from your first glance. Look left and right up and down the surf zone – identify gutters, sandbars (evidenced by waves breaking a distance offshore then reforming as green unbroken waves as they pass over the deeper water of the gutter closer to shore), and places where rips have cut through sandbars to feed water back out to sea. Is there a single gutter and sandbar, or a series of gutters and sandbars extending well beyond the shore? See if you can work out which way water is flowing in the gutter/s between the shore and a sandbar (at some points on the beach, this direction can be opposite to the direction of tidal flow beyond the sandbar/s). Observe the long line of a breaking wave and note that there may be sections or gaps where the wave does not break at all (because the water is a little deeper under such a gap). The gap could well be where a rip flows out to sea. If you identify where you think there is a rip, note its position relative to landmarks on the shore to assist in your decision making once in the water.

One fact that can always be relied upon is that if there are waves breaking and water washing back and forth at the water’s edge, gravity will cause the water temporarily transported above its natural level to return to that level as soon as the force washing it ashore ceases. Even though it might not be visible, its presence can be deduced, and an educated guess may be possible as to its location. But knowing there are rips but not knowing exactly where they are, in conditions that are rough, might well be enough reason to exercise the skill every ocean swimmer should possess – making an informed decision as to when not to swim.

Any rip of substance can be detected by a swimmer in the water once they are in the rip. The water is usually murkier than the water around it (due to sand etc being picked up by the rip in the shallows and carried seaward), the texture of the surface where there is a rip differs (often in subtle ways) from the surface texture of surrounding water (because there are conflicting flow directions), and of course the swimmer will be carried away from the shore – sometimes at 90° and sometimes at a lesser angle. Because the swimmer is being carried by a moving body of water, there is no sense of a current pushing against the swimmer whose feet are not touching the seabed. The fact of heading seaward is not always immediately apparent. It is important to develop the skill of being able to quickly assess by observation whether or not a current is taking you somewhere unplanned. Lining up two objects some distance apart while treading water and observing their apparent movement (if any) is one way to do this. If this can be done in two different directions separated by 90° or at least a significant angle, a very accurate assessment of drift (either due to a rip or a tidal current) can be made.

Swimming against a strong current (assume no wind or waves for present purposes) is no harder than swimming with such a current. You will just cover a shorter distance in a given number of minutes when swimming against the current than you would if there was no current (and a longer distance when swimming with the current). Or put another way, at a constant stroke rate and stroke distance it will take you longer to swim 1000m against the current than with the current. What the current changes is the speed at which you pass over the seabed – your speed through the water stays the same whichever direction you swim. This is illustrated by the fact that if you stand in shallow water in a flowing river, you will feel the current on the upstream side of your body. But if you tread water in the same flowing river, you will not feel any current on any side of your body because you are moving with the flowing body of water.

That said, when there is a strong wind blowing across the surface of the sea, swimming against the wind will be quite a different experience to swimming with the wind behind you. It takes more effort to swim into the wind when it is creating waves and chop than it does to swim with the wind behind you, in the same direction as the wind, waves and chop.

A myth that seems to enjoy currency in some circles is that a rip in the ocean will pull you under the surface. It won’t.

While I’m debunking myths, here is another: an out and back swim of a given distance with a constant current (head current one way, following current the other way) will take no longer than the same out and back swim in nil current because the time you lose on the way out you gain on the way back. This is incorrect. The total time for the round trip swim into and then with the current will always take longer.

An essential ocean swimming skill is to maintain situational awareness at all times – don’t just swim around without regular reference to the shore and landmarks. If you do, you could find when you eventually assess your location that you have been carried hundreds of metres sideways or out to sea by a rip (and/or tidal currents). The response to becoming aware you are swimming in a current might be as simple as adding a drift angle to your swim (aim a bit left or right of where you want to go so that you track directly there) or altering course significantly to get away from the current if it is not assisting you, or making and executing a plan to return to shore.

Many of the photos below utilise a ‘photo-compare’ function. The round button in the middle with a left and right arrow allows you to use your cursor (hold it over the button and press) to slide the divider fully right (which displays the full first image) and fully left (displaying the full second image). Where the slider is used, the first photo is of ocean water with a rip, and the second is the same image with an arrow or arrows pointing out the location of the rip.

Apollo Bay

Castle Cove

Gibson Steps

The following three photos were taken in rapid succession and show a rip undergoing changes quite rapidly over a short period of time.

Johanna

Marengo (Mounts Bay)

Where a river, creek or drain enters the ocean expect uneven depth of the seabed and rips and currents in the immediate vicinity.

Storm Point, Smythes Creek, Sledgehammers

Sledgehammers on a rougher day, with more rips in action.

Logans Beach, Warrnambool

Lorne

Port Campbell

The Southern Ocean at Port Campbell can be wild. There are many stories of shipwrecks in this area. The bay near the town is narrow and less than a km in length. If faces south west and receives the full force of wind and weather and swell from that direction.

If you unexpectedly find yourself in a rip taking you somewhere you don’t want to go

Don’t panic. This is more easily said than done. Being uncomfortable about your position is OK, panicking about it is not and may well cause you to drown. If you suddenly realise you are making zero progress towards your aiming point (the shore) or that you are going out to sea when you thought you were swimming to shore, don’t just put the head down and start swimming harder. Best to tread water while you have a think about the situation and allow a few moments for any adrenaline rush from being out of your depth while going in a direction you didn’t want to be going to ease off a little.

If you are in unpleasantly turbulent water and there is quieter water in close proximity (even if it is the unbroken water beyond the surf zone) consider drifting or swimming there at an easy pace to regroup. If you are in deeper green water beyond the surf zone, the rip will have eased up or stopped. You are unlikely to come up with a quality plan if you remain in 2 metres or less of water over a sandbar where the breaking waves are big enough to throw you around and repeatedly thump you into the sand.

Come up with a logical plan. Your opportunity to swim back to shore will be either to your left or right if you are facing shore in or near the rip or just beyond the surf zone (where the rip has faded or ended). First line up a near and a far object on the shore to see whether you are drifting left or right. If you are it will most likely be tidal drift, but it could also be a rip taking you away from shore on an angle. If there is a strong drift, its direction is a consideration in whether you go left or right before heading back to shore.You must think your way out of the situation, not frantically try to power your way out of it.

Be prepared to amend your plan if execution of it is seriously not working out as hoped.

If the breaking waves are not making life too uncomfortable for you in the surf zone, look for an area of white water where waves are breaking as each set comes through and swim parallel to the shore until you have that area of breaking waves directly between you and the beach. This will usually take you out of the side of the rip. Then head to shore.

If you have swum out to the green water just beyond the surf zone, when a set of waves is breaking between you and the shore, sometimes you can see where the higher sections of the wave are (over the shallower seabed which can be your ticket to the shore), and gaps where the breaking waves are lower or not breaking at all (deeper water where a rip may be flowing out). Your route to shore will be through the shallower water, not the deeper water where the water may well be moving out to sea.

If you are in the green water beyond the surf zone looking for the best option to get to shore, provided you are not cold or exhausted, it may be worth treading water while you carefully watch a couple of sets of waves go through. You can then time your return to shore based on the sets of waves you observed. In small to moderate surf you may seek to go ashore with wave assist, or in bigger surf you may wish to wait for a lull between sets to head for shore. The timing of your swim ashore can be everything in this situation.

Pick a landmark to aim for so that you ensure you stay on track and don’t drift back into the rip. If you are drifting left or right as you swim towards shore, apply an angle of drift to help you track in a straight line. Check every few strokes by lifting your head a little and looking forward that you are staying on track. Take regular glances back over your shoulder as you swim through the surf zone to keep an eye on waves approaching you. If it is a completely broken wave of manageable size you could accelerate a bit as it reaches you, or perhaps even body surf it if you have that skill. If it is a large broken wave you might pause as it approaches, turn and face it, and duck dive or ‘pin drop’ to let it pass over you – then resume swimming towards shore.

If you have swum towards shore through a surf zone you will reach shallow water where you can walk to shore. But if the surf zone you have swum through was over a sandbar you may encounter a gutter where the waves are not breaking as much or at all. Don’t relax completely, because if conditions were enough to form a rip that carried you out a ways, the water in the gutter is probably flowing strongly too, feeding the nearest rip. You may need to point towards somewhere left or right of your target on the shore to avoid drifting parallel to the beach in the gutter. In such conditions the gutter may well be too deep to stand in.

Alternatives to swimming directly back to shore. If you are swimming in a curved bay with a nearby point (what is ‘near’ depends on your distance swimming ability), and you find yourself out in the green water just beyond the surf zone and looking for the best way back to shore, swimming parallel to shore to go ashore at the point can be considered if swimming through the surf zone looks entirely unattractive or unsafe for you. But remember that most points have a rip running out to sea alongside the rock shelf which will have to be contended with if this option is taken.

In a curved bay, I have noticed that the sand bars are often further offshore where the beach has a marked change in direction, than where the beach is straight. So an option to consider in that situation is to select a spot for your swim ashore which has less distance of white water to swim through ie on a straight section of the beach. This may involve swimming parallel to the beach for some distance to find the shortest appropriate swim to shore through the surf.

Note that in big swell, where the water is not too shallow, duck diving under a breaking wave works very well at avoiding turbulence even if it requires duck diving a couple of metres or more below the wave. But as the water gets shallower, a point is reached where duck diving under the wave does not avoid the turbulence and you will get rolled and tossed around as each wave passes over you. Don’t linger in such a zone – you need to get to either shallower water where you can safely stand or to deeper water (either by swimming towards a gutter closer to shore and then to shore, or out to sea beyond the surf zone where the waves while large are not breaking) where you are not receiving a flogging with every wave. The latter is quickly exhausting.

A Reminiscence

I have been swimming at this Victorian west coast beach for years. The swim I am about to recount happened not on a half tide on a sunny day with small surf as shown in the satellite photos below, but on a cold mind-winter’s morning a few years ago. The water’s edge was much closer to the dunes than shown in the photo, and the gutter was wider than shown in the photo.

There was a solid swell and a high tide with a strong offshore wind. It was overcast and showery and the line of the horizon across the sea was notchy indicating big swell way out to sea across the entrance to Bass Strait. The water would’ve been around 12-13°C. The air temp was less than that with wind chill in low single figures. I was wearing a good quality winter wetsuit, a neoprene armless vest under it and a lined cap. I wasn’t cold. I was swimming fit and had swum virtually daily since summer which included some long distance swimming races of distances up to 5kms.

I paused before entering the water a bit south of Milford Creek as the waves were breaking quite a way out, probably beyond the sandbar. The distance across the gutter to the sandbar was only about 50m. Being a bit daunted by the size of the breaking waves and the distance I’d have to swim to get to the green water out the back for my swim to the harbour wall, I paused and watched a couple of sets come through. They weren’t getting smaller, so I decided to take it in stages by swimming across the gutter (where I knew I’d be out of my depth) to the sandbar where I believed the water would be shallow enough to stand in. I figured that would be a good vantage point from which to assess whether to swim back to the beach (a short and easy swim) or to continue to swim through the surf zone to the deep water out the back and then down to the wall – a swim I have done many times in widely varying conditions.

I quickly reached the breaking waves over the sandbar and while at a stretch my big toe occasionally brushed the sand, I was out of my depth. That was OK and had happened before. The brief 50m or so swim to the sandbar revealed a steady current to the north. That was pretty standard in such conditions. I was having to keep ducking under breaking waves while I was over the sandbar. Some I bobbed down for, others I duck dived under. Both techniques saw me getting rolled and bounced around rather than cleanly making it under the waves. I swam out just a bit further thinking the water might be a bit deeper giving me room to dive under them with comfort before I decided whether to continue or retreat. But the waves were still breaking heavily and the water while not deep enough for comfortable duck diving, was not shallow enough for me to stand.

The view out to sea revealed waves that certainly looked bigger than they had from the shore, and they probably were. The breaking waves were a very substantial wall of advancing white water. Diving under each wave was the only option. A retreat back to shore was suddenly looking very attractive. I realised I had been swept up the beach a bit and was some distance north of where I entered the water. I headed back towards the edge of the gutter for what I still believed would be the short swim back to shore, albeit in water too deep to stand in. On entering the gutter I quickly realised I was going north and that my distance from shore was increasing. There is a break in the sandbar near where the Milford Creek runs into the sea, and (as I later discovered) the gutter I was in was feeding into the rip there.

So I only really had one option, and that was to swim away from the shore until I was beyond the breaking waves and in deeper water. I duck dived every approaching breaking wave as I swam seawards again across the sandbar. Some gave me a disorienting somersault or two and hard contact with the sand. I swam past the outer edge of the sandbar where the breaking waves usually stop, but there were large enough sets rolling in that some were breaking out to sea beyond the sandbar. I have seen this before, but not often while swimming. Once I cleared the sandbar I was in deeper water and while I couldn’t reach the sand when I duck dived, I could go deep enough to avoid the main turbulence of the breaking waves. On a few occasions I dived deep enough for my ears to pop which happens to me when I’m snorkelling at a depth of 8-10 feet or more. While I was heading away from shore, as soon as I stopped getting thrown around out of control under breaking waves I began to feel that my situation was improving a little.

I was relieved when after diving under yet another sizeable breaking wave out the back I surfaced and saw that there were no more breaking waves on my horizon. I stopped swimming and trod water. I was about 150m offshore (out from the waterline) according to my Garmin GPS watch. I realised I was breathing harder than usual and that my pulse rate was up. I didn’t feel panicked, but I knew I was closer to it than I should have been. I looked around and checked the tidal current – it was not huge and was going south. That was good – a tail current for the longer swim to the harbour wall at the southern end of the beach. I was now in a familiar situation – out the back in green water with an entirely manageable swim south to the harbour wall – the final leg of my original plan when I entered the water.

I couldn’t see the shore when I was in the trough between lines of swell. I had a great view in all directions from the crests. The seas felt big. Normally I love swimming in rising and falling green swell lines. I wasn’t quite feeling the love at this stage but I did feel that the situation was now under control. My breathing had slowed and I felt comfortable.

The swim to the beach at the southern end of the bay was uneventful. The swell size started to ease once I got south of the SLSC into the relatively protected corner of the bay. While I was a little further offshore than usual, deep water is deep water. I had a following current and the swim was entirely safe. I was enjoying the swim well before I swam past the rock wall of the harbour and into the shallows in the corner. Despite having friends swimming in the bay that morning, I didn’t see any of them. Our long habit of swimming together is really a habit of swimming at the same time at the same beach, but for all practical purposes, solo.

Postscript: I should’ve listened to the inner voice telling me I didn’t like the look of the size and extent of the surf where I went in. I allowed confidence to overrule caution. When I finally got out the back beyond the breaking waves, the shore looked a very long way away. I should’ve realised that on the high tide in that swell I wouldn’t be able to stand on the sandbar. I should’ve looked at the conditions a bit longer before going in, and I might have spotted the rip that I encountered. I shouldn’t have felt uncomfortable about the longer than usual swim through the solid surf zone. I have swum similar distances out through solid surf before at the start of a distance swim. But I think it was the fact that I decided to swim back to shore (and attempted to do so) but couldn’t get there that heightened my sense of discomfort about having no other option but to keep swimming out to sea.

I was in the water for longer than I had intended, and my warm wetsuit, vest and cap served me well. I wasn’t cold at any point. I was distance swimming fit and had confidence that subject to hypothermia I had a much greater distance in me than I would need to swim to get to shore.

I have had a handful of rip episodes over the years. Each one has taught me valuable lessons. I have heard pilots say that experience is the sum of the frights you survive.