waves, billows, Poland
波 centers on moving water: waves and billows. The meaning 'Poland' is a phonetic abbreviation unrelated to the water sense.
波 combines 氵 (water) with 皮, which likely contributes the sound and the idea of a surface that moves or undulates like skin or hide.
Water 氵 with a skin-like surface 皮: imagine the surface of the water rippling like skin, forming waves.
For ハ, picture a wave laughing 'ha!' as it crashes: ha -> ハ.
wave; billow; ripple; breaker; swell
radio wave; reception; signal
tsunami; tidal wave
frequency (esp. of waveforms)
ground wave; terrestrial broadcast signal (i.e. not satellite)
Naniwa (former name for Osaka region)
wave motion; undulation; surge
sound wave; acoustic wave
electromagnetic wave
wavelength
Tanba (former province located in parts of present-day Kyoto, Hyogo and Osaka prefectures)
ripple; ring on the water
Awa (former province located in present-day Tokushima Prefecture)
Iwanami (publisher)
spread; extension; influence; aftereffect; ripple
wavy form; ripply shape
brain waves
disturbance; trouble; commotion; uproar; turmoil
ripple (on water); wavelets
cycle; wave; frequency