Peter, I was able to operate the model 35 today.Quality is what I expected,owning a small land unit. We operated it on battery and manually.Physical effort was not dissimilar to a bicycle pump and the water is quite palatable.It has indeed been superceded by a model 40,which I understand has almost half the parts.The periodic factory maintainance seems to consist of careful O-ring replacement. Im told many users elect to do this themselves. I will find out if this affects any warranty.Ill try to locate a Model40.Im in Southern California and near the ocean,so there are plenty of marine dealers.Ill see what the stocks of 35s are,and if there is any price break.<br><br>