Streamlining and Submarines

Reducing resistance in a swimmer should be a top technical priority for all coaches, taking precedence before any changes to improve propulsion. Although, the former will have the consequence of improving the latter. The most fundamental way to reduce drag is through streamlining. A streamlined body is one which is horizontal in the water – this includes the head and body; the flatter, the less resistance created.

– Streamlined swimmer = greater velocity and distance per stroke.


Let’s start with an analogy to highlight this point. Take a submarine on the surface of the water; no need to imagine it, here is a picture:


Here you see the front of the submarine minimally disturbing the water, in fact, it is slightly underwater. Now take a look at the structure protruding from the submarine; here you see a great amount of drag being created – evident from the white water.


This white water effect occurs similarly (not to such a scale of course) from the head of a swimmer breaking the surface of the water. Ideally, the frontcrawl stroke needs to replicate the front of the ‘sub’. Here are the instruction points which should be communicated to the swimmer in order to achieve this position:

– Look directly down at the bottom of the pool;
– The tip of the swimmers’ buttocks should be at a level height to that of the top of the swimmer’s head;
– There should be some water which travels over the swimmer’s cap.


These principles are much the same in the case of backstroke, apart from the obvious difference.

– Head should be back, looking up at the ceiling;
– Water should travel over the face;
– Both ears should be submerged;
– Top of hips will be in line with the top of chest and face.

Breaststroke and Butterfly

During breaststroke and butterfly, it is not possible to remain in a streamlined position at all times; however, it is important to continue in the latter position for as long as possible. When a breath is needed, the athlete should be trained in movements which will cause the least amount of disruption to the water.

Firstly, butterfly. There are two main factors in the stroke which should be considered:

– Increasing size of kick = increased resistance:

Bigger kicks tend to cause greater movement at the hips, which both create a fairly slow kick rate; this reduces the opportunities to initiate a propulsive action. The increased drag eventually outweighs any propulsion.

– Increase in vertical height = increase in resistance:

Frontal resistance is substantially increased when a swimmer’s head and shoulders are lifted vertically out of the water, whether he/she is breathing or not. There is also the added resistance which comes from the swimmer returning from this high position and often ‘slaps’ down on the water.

A ‘see-saw’ movement is observed in many swimmers. They drive their head and shoulders down into the water, the hips lift as a consequence, and the feet kick down. The swimmer expends a significant amount of energy swimming like this. This movement is also caused by an arm recovery which travels, unnecessarily, high on exit.

In butterfly, to create an optimal streamlined position, the following points should be adhered to:

– Breathing should be low and forward;
– Reduce the vertical movements of the arm entry, exit and the kick where possible;
– Keep the body in a streamlined position for as long as possible.

In breaststroke, the breathing action very much determines the amount of streamlining which is achieved. A ‘see-saw’ is sometimes also seen in the breaststroke. The points below, govern what breaststroke technical points should be followed to achieve the most streamlined position possible; which are almost identical to the fly stroke:

– Breathing should be low and forward;
– Any ‘see-saw’ movements should be completely discouraged – this includes downward movement of arm or raising of hips;
– Keep the body in a streamlined position for as long as possible.

If changes in other elements such as arm action, kick or breathing are required to improve streamlining, these should be instructed separately, not all at once.

Improvements can be verified through stroke counting, as improved streamlining should account for greater distance per stroke.

A final point to make is that all these instructions should be conducted at race-pace velocities as soon, after the movement has been established at less-than-race-pace speeds, as possible. Technique is closely related to velocity. Technique at slow speeds will unlikely be reproduced at race-pace.

Yours in Swimming,



2 thoughts on “Streamlining and Submarines

  1. I agree with everything you said, and I constantly try to reinforce all of these actions with my swimmers, but they have such a hard time with maintaining the lower head or body positions (all 10 and under swimmers). Any suggestions that will help me get through to them, especially in Butterfly?

    • I am very familiar with the challenge of coaching swimmers aged 10U, it takes a lot of practice and skill. An effective way of teaching kids about body position is to do some balance drills including sculling. Getting the swimmers to simple lie flat on their front (or back) and instructing them to lift their head, and move it in different ways, to see what happens is a good way of helping them understand the importance of the head in relation to the body.

      Sculling is an ideal way to practice maintaining a correct posture at the surface of the water – as the swimmer must keep a strong core and a position which is completely in line to go through the water easily.

      The kick on side drills are a great, progressive way to get young kids to achieve the correct – rotated – position. I should make it clear what I mean by kick on side: The body should be rotated, as it would be in the stroke, not completely on their side (on their back or front). The head should be either facing directly up or down, depending on the stroke and should NOT move at all – unless taking a quick breath when doing the frontcrawl position (this should be kept to a minimum).

      A progressive set for backstroke could be as follows:

      2 x 25 Kick on side (KOS) – change arm after 25;
      2 x 25 KOS – change arm at half way point (12.5m);
      2 x 25 KOS hold each arm for 12 kicks;
      2 x 25 KOS hold for 6 kicks;
      50 Backstroke.

      I suggested 2 x 25, however, I would not move on until each part of set is mastered – this might be 6 x 25 on each – or some more on other.

      Hope this helps.

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