We found out after decades of experience that showertubs are quitte easy to make much safer, since weak, sick, injured, small, elderly or young people are more vulnerable to tripping when getting in or out, and even normal-sized healthy adults can make a misstep. People die or get crippled from such falls in bathrooms every day, and yet this is unnecessary. Baths are a waste of water and time, and often if there is a showertub in the house, there is also a plain old bathtub as well (unused by us). The reason tubs are in most houses is because of the need to bathe kids, so tubs increase resale value and are a sticking point in house sales.
So the high walls on the showertub are nothing but a needless liability. The wall of our showertub was 12.75 inches tall but now it is a mere 3.44 inches. And with me having a bad back that had just degenerated into a very bad back, we knew we had to act. I could just barely step over such a high obstruction, and it was painful to do so—and dangerous!
So we searched the internet and found that there is a whole industry centered on bathroom remodels and this is one of the newest offerings: the bathtub saddle. This dovetails with the aging of the population—more and more people are concerned with home safety and remodeling to improve safety. See Peoria Fiberglass Inc., which is where we found a good deal for $295 bucks. The saddles are totally custom made according to tub measurements you send to them. They are well made and look good, too. We recommend them. They've eliminated a source of stress, danger, and pain in our life—thanks, people! It cost us another $250 to get our super-talented handyman to install the saddle. Total cost: $545—much better than remodeling places we contacted.
Internet research determined that the showertub saddles usually have a shower curtain in the tub to prevent splashing the bathroom floor. We liked our door a lot, and we left it as is. We had to remove a piece of the gold drip-bar (we caulked the cut ends). We fastened a piece of stiff, clear acrylic plastic to the bottom of the door that loosely fit the saddle opening—this keeps the water in the tub where it belongs. It's a splash guard. We didn't see any other door-and-saddle combos online—with or without a splash guard. Does this mean we're the first?
Notch-Cut and Convert Your Tub and E\Z Step tub to shower conversion kit were considered and rejected, because they were either lots more expensive or they had no installers in our area, or Kister's Convert Your Tub was $295 and custom made but our handyman wanted Peoria because they make one-piece saddles, whereas Kister stuff is three pieces—more chance of problems.
Note: The prep work for the cutting of the tub is unusual in that you need to cover every square inch of your bathroom with plastic drop cloths, plastic film from a roll, newspaper, painters' drop cloths, or whatever. The alternative is to spend many hours cleaning ceilings, walls, floors, counters, shades, curtains, etc., after the cutting is done. Fiberglass dust is the most harmful so not wearing a respirator when cutting or cleaning is a really bad idea, but all tub materials require respirators during cutting and a closed bathroom door with rags blocking the crack underneath. If it's a porcelain-covered iron tub, the particles from cutters and grinders will not only smell bad, but present themselves as a greasy, nasty, hard-to-remove film that is nasty to get off. We used a sponge mop, and various cleaners like Oxyclean and Comet on ceilings, floors, and walls. Even with the bathroom door closed, particles got under the door and messed up the room next to the bathroom as well. Make sure the exhaust fan is on in the tub room during the cutting. If there was ever a situation illustrating that an ounce of prevention is worth a pound of cure, THIS is that situation! Choosing between 30 minutes of taping plastic on walls (including all tub and tile walls except the part to be cut!) and a day or two of cleaning nasty black crud on walls, ceilings, floors, etc., should be easy for most people. The tub saddle websites need to give clearer warnings and prep work instructions.