Other things related to sealevel data: [[,sealevel-method,
[[<-,sealevel-method,
as.sealevel,
plot,sealevel-method,
read.sealevel,
sealevel-class,
sealevelTuktoyaktuk,
sealevel,
summary,sealevel-method
Other functions that subset oce objects: subset,adp-method,
subset,adv-method,
subset,amsr-method,
subset,argo-method,
subset,cm-method,
subset,coastline-method,
subset,ctd-method,
subset,echosounder-method,
subset,lobo-method,
subset,met-method,
subset,oce-method,
subset,odf-method,
subset,rsk-method,
subset,section-method,
subset,topo-method