Extra water tank.
That could well be but I know that in the case of the E31, extra water tankage was a function of the depth of the original purchasers pockets. For that matter, the list is endless as to all the "extras" available on the E31. As an example, tiller steering was standard with a wheel being extra and the list literally goes on for a full page of options. Glyn Judson, E31 hull #55, the Dawn Treader, Marina del Rey, CA
That could well be but I know that in the case of the E31, extra water tankage was a function of the depth of the original purchasers pockets. For that matter, the list is endless as to all the "extras" available on the E31. As an example, tiller steering was standard with a wheel being extra and the list literally goes on for a full page of options. Glyn Judson, E31 hull #55, the Dawn Treader, Marina del Rey, CA