A second vote for insuremytrip.com. I have used both Travel Guard and CSA and have been pleased with claims processes at both. One word of caution is that you also check with your TA in addition to insuremytrip. My agent gets "group rates" with CSA that are undercutting insuremytrip.com rates.
"Carpe diem quam minimum credula postero"
Seven Seas Explorer - Miami - Venice - Mar 2017
Silverseas Explorer - Arctic - Aug 2017
Seven Seas Voyager - Rome to Beijing - Oct 2017
Seven Seas Mariner - Lima to Buenos Aires - Jan 2018
Silverseas Explorer - Siberia - Jul 2018
Seven Seas Mariner - Australia Circumnavigation - Dec 2018