01) A groundsheet is an absolute must and if you can, place your bivvy on the driest area of the swim. Some waters actually allow straw to be put down, so if you can, get a good layer under the groundsheet before putting the bivvy up.
02) When you put the bivvy up, make sure the mud flaps are under the groundsheet thus reducing draughts.
03) Peg the bivvy down as tight as you can and try to get the bivvy skin drum tight.
04) Winter skins really do make a difference, not only reducing condensation, but assisting in heat loss. They are only effective if they too are taught and DON’T TOUCH the bivvy skin.
05) Place your unhooking mat over the top of the bivvy, laying it on the tension bars.
06) There are things you can do to reduce condensation; a winter skin helps, but so does boiling the kettle outside the bivvy.
07) If you can, have another smaller groundsheet, ideally in neoprene that is slightly larger in footprint size to your bedchair and place this below the bedchair. If this is too much hassle, buy a small doormat that you can put your feet on when sitting in the bivvy. Also, keep your bedchair as high off the ground as is possible.
08) Candle lights are brilliant in the winter nights. You can buy them from camping shops as well as tackle shops, and the difference they make is phenomenal to the mind alone. Buy a reflector to keep the light in the area you want it, and yes, they even warm your hands.
09) You might want to be ‘hard’ but keep all the sides of the bivvy down. If it’s really bitter then close the door and watch the water through either the clear panel or mozzi panel.
10) Don’t be tempted to shut everything up and keep the stove running; this is potentially lethal. There are plenty of ways of keeping warm without doing this and if it is that cold, get in the bag or pack up and go home, as in all probability the lake will be beginning to freeze.