I have lost
several M72 to sinking as well. I finally bought several of the M34 and was not happy with the range. I exchanged them for the M36 which has a 6 watt radio
but uses the cheaper and shorter range antenna
from the M34. I contacted Icom about the antenna
issue and the connectors on the M72 hi range antenna is different than the M34 and M36. At the end of the day the M72 is king - great range, great battery and compact size - but they sink. The M34 and M36 are larger larger in size to the M72 and the also will sink if extended battery packs are attached. The M34 is my last choice of the 3. I bought my M36 at west marine
a few months ago for $189 with a $50 rebate so they ended up being about $139. One other issue, the M36 is tough to remove from the charging
craddle - a real fight sometimes.