The Flag

Divers are very hard to spot in the water, especially in rough seas, and so I always take a flag with me on open water dives. It comes with me not just on UK dives, but abroad as well. On a recent holiday to the Red Sea, we got split up from the rest of the group. There were a dozen boats at the site, and hundreds of divers in the water. Fortunately I was the only one with a flag, and we were easily identified and picked up promptly. The skipper was so delighted with my flag that I gave it to him at the end of a holiday. You can make yourself a flag for less than £5, and it's easy to do, so there's no excuse not to.

To make a flag you will need:

• A 2m length of 25mm diameter electrical trunking
• 2 straight connectors for the above
• A square of rip-stop nylon
• Just over 2m of bungee
• 2 cord ends
• Superglue as required

Electrical trunking is a narrow diameter PVC pipe. It is used for burying cables in the garden. You can buy it in B&Q, but be warned - it's not near the other PVC pipes such as drainpipes, like you would expect it to be, but with all other electrical stuff like plug sockets and so on. You also need two straight connectors. These often live near the trunking. B&Q will also sell you the bungee cord you need.

Rip-stop nylon is a special material that is light and, erm, doesn't rip easily. It's often used to make kites and sails for dingies. You can buy it online from www.pointnorth.co.uk, or in the real world from Decathlon, where it is in the Sailing section.

The last thing you need are two cord-ends. Cord-ends are similar to giant beads: large plastic balls with holes drilled in them. The hole must be just bigger than your bungee cord, and the diameter of the ball itself must be bigger than the diameter of the electrical trunking. I got mine from www.pointnorth.co.uk again, but be careful as they do different sizes. Alternatively you can buy two large plastic balls and drill 5mm holes in them.

So ingredients assembled, how do we go about making the flag? The first thing we need to do is make our collapsing pole. Take your electrical trunking, and saw it into three sections. The length of these sections depends on the length of your trunking connectors. Mine are 4cm long, and so I saw my trunking into two lengths 66cm long, and the one which is 68cm long.

Sawing lengths of PVC pipe often leaves rough edges behind, and so I like to melt the sawn ends of the pipe in a gas flame to tidy them up. Be careful though, as hot plastic is sticky and so can give you a very nasty burn.

Sawing complete, take one of your trunking connectors, and superglue it to the end of one of the shorter sections. Take the other trunking connector, and glue this to the other shorter section. You should now have three pieces of trunking of equal lengths. If they're not quite equal, and you're a perfectionist, you can even up the lengths, but minor difference in length are unimportant.

Now we will use the bungee to make our three pieces of pipe into a collapsing pole. Take the bungee and tie a stopping knot in one end. Thread on a cord-end, then a piece of pipe with a connector on one end, then the connectorless pipe, then the other piece of trunking with glued connector. Then put on the second cord-end. Make sure that you have the connectors in the right position (ie not at either end of the pole). If you pull the bungee tight, the pieces of pipe should come together to make a two metre long pole. Keeping the bungee under tension (you may need someone to hold one end, but do not ask Pippa as she will let go, leaving you with an expensive dental bill) tie another stopping knot in the other end of the bungee. Ta-daa - a collapsing pole.

Pole complete, we need to make the flag itself. Take the rip-stop nylon and cut it into a square, or indeed any shape you like. Rip stop nylon differs from ordinary cloth in that it has threads along it both vertically and horizontally. These prevent tears from travelling through the fabric. These threads form a simple grid that makes sewing simple. You need to fold about an inch of the material back on itself and stitch it securely. The fold you create will allow you to thread the material on to the pole to complete your flag.