In the summer I hate watching the bathwater from my kid's bath go down the drain when I've got a garden to water. Rather than bucket brigade the water out, I found an ingenious way to siphon the water out with the garden hose into the garden. It saves money, reuses water and is free. The only cost is perhaps having your neighbors give you a wayward glance with an arched eyebrow. This is so easy it takes two steps.
Step 1: Siphoning Water From a Bathtub Into Your Garden
After you've filled up the tub from a bath or shower, drag in the garden hose. Leave the other end connected to the spigot outside. Put the end of the hose into the tub next to the drain. Pin the hose down on the rim of the tub with something. An upturned potty stool works like a charm. Now, be sure to take toddler with you outside so she doesn't cause a flood during the next step.
Step 2: Rack the Tub
Go outside and gently turn the water on. Your goal is to fill the hose up with water. After 10 seconds or so water should be flowing into the tub. Turn the water off and unscrew the hose from the spigot. Water will now rack out of the tub using gravity and flow in reverse. Easy peasy. Your raspberries thank you.