I've got a pretty long (5 feet/1.5m) bungee looped through my Sistema bottle, which is then clipped with a hook into the toe strap. The boottle is tall enough to be supported by the two bungees of the toe strap, so the bottle doesn't fall out unless I go for a swim. The bungee is long enough so I can drink without unclipping and it hasn't got into my way during racing. Obviously if I do capsize, the bottle is tethered to the boat. Sistema sell a larger diameter bottle, which doesn't fit into the hull moulding.
I've accepted that the bottle will come out of the holder sometimes in a capsize. So it now has a length of 2 mm bungee cord tied to the bottle neck, and plastic clip at the other end, clipped to the toe strap. That way at least it never drifts away from the boat.
I like your idea, I lost a bottle overboard this year and I would like to see a good solution to the problem of keeping a bottle(whatever its size/shape) in the boat. I've improved my bottle retention a bit by twisting the toestrap elastic to create a bit of backward pressure which clamps it to the bottle holder a bit more securely.
The Aero has a bottle holder moulded in the floor of the hull by the transom The bottle will only stay in place with some assistance in the shock cord holding the toe-strap up.
Peter Barton, in his instructional videos uses a plastic ring to achieve this. I did not have any plastic rings so i printed up a little bottle holder that serves the same purpose.
Photos to show - Peter Bartons original set-up Bottle holder on boat Bottle holder on bottle
Please can you confirm the legality of the arrangment
