diff --git a/DESCRIPTION b/DESCRIPTION
index 5796c1e..e42b771 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -16,6 +16,7 @@ Imports:
     archive,
     assertthat,
     aws.s3 (>= 0.3.21),
+    CopernicusMarine,
     curl,
     fs,
     httr,
diff --git a/NAMESPACE b/NAMESPACE
index e0fc642..f786004 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -18,6 +18,7 @@ export(bb_fingerprint)
 export(bb_get)
 export(bb_gunzip)
 export(bb_handler_aws_s3)
+export(bb_handler_copernicus)
 export(bb_handler_earthdata)
 export(bb_handler_oceandata)
 export(bb_handler_rget)
diff --git a/R/copernicus_handler.R b/R/copernicus_handler.R
new file mode 100644
index 0000000..0066293
--- /dev/null
+++ b/R/copernicus_handler.R
@@ -0,0 +1,104 @@
+#' Handler for Copernicus Marine datasets
+#'
+#' This is a handler function to be used with data sets from Copernicus Marine. This function is not intended to be called directly, but rather is specified as a \code{method} option in \code{\link{bb_source}}.
+#'
+#' Note that users will need a Copernicus login.
+#'
+#' @references https://help.marine.copernicus.eu/en/collections/4060068-copernicus-marine-toolbox
+#' @param product string: the desired Copernicus marine product. See \code{\link[CopernicusMarine]{cms_products_list}}
+# @param layer string: (optional) the layer within a product. See \code{\link[CopernicusMarine]{cms_product_details}}
+#' @param ... : parameters passed to \code{\link{bb_rget}}
+#'
+#' @return TRUE on success
+#'
+#' @export
+bb_handler_copernicus <- function(product, ...) { ##layer,
+    assert_that(is.string(product), nzchar(product))
+    ##if (!missing(layer)) {
+    ##    if (!is.null(layer)) assert_that(is.string(layer), nzchar(layer))
+    ##} else {
+    ##    layer <- NULL
+    ##}
+    do.call(bb_handler_copernicus_inner, list(..., product = product))##, layer = layer))
+}
+
+
+# @param config bb_config: a bowerbird configuration (as returned by \code{bb_config}) with a single data source
+# @param verbose logical: if TRUE, provide additional progress output
+# @param local_dir_only logical: if TRUE, just return the local directory into which files from this data source would be saved
+bb_handler_copernicus_inner <- function(config, verbose = FALSE, local_dir_only = FALSE, product, ...) { ## layer = NULL
+    assert_that(is(config, "bb_config"))
+    assert_that(nrow(bb_data_sources(config)) == 1)
+    assert_that(is.flag(verbose), !is.na(verbose))
+    assert_that(is.flag(local_dir_only), !is.na(local_dir_only))
+    assert_that(is.string(product), nzchar(product))
+    ##if (!is.null(layer)) assert_that(is.string(layer), nzchar(layer))
+    dots <- list(...)
+
+    thisds <- bb_data_sources(config) ## user and password info will be in here
+    this_att <- bb_settings(config)
+
+
+    if (local_dir_only) {
+        ## actual source URLs look like e.g. https://s3.waw3-1.cloudferro.com/mdl-native-07/native/SEALEVEL_GLO_PHY_L4_NRT_008_046/cmems_obs-sl_glo_phy-ssh_nrt_allsat-l4-duacs-0.25deg_P1D_202311/2022/01/nrt_global_allsat_phy_l4_20220101_20220107.nc
+        ## but it seems plausible that the server/bucket might change over time
+        ## so we will store locally under data.marine.copernicus.eu/<product>/
+        return(file.path(this_att$local_file_root, "data.marine.copernicus.eu", product))
+    }
+
+##    if (is.null(thisds$user) || is.null(thisds$password) || na_or_empty(thisds$user) || na_or_empty(thisds$password)) stop(sprintf("Copernicus sources require a login: provide your user and password in the source configuration"))
+    if (verbose) cat("Downloading file list ... \n")
+    myfiles <- CopernicusMarine::cms_list_stac_files(product) ## layer is ignored in this?
+    myfiles$url <- paste0("https://", file.path(myfiles$home, myfiles$native, myfiles$current_path))
+    ## take the `current_path` of each file and find the product ID
+    pidx <- stringr::str_locate(myfiles$current_path, stringr::fixed(paste0(product, "/")))
+    ## use the section of `current_path` from the product ID onwards as the local directory under "data.marine.copernicus.eu"
+    myfiles$local_filename <- file.path("data.marine.copernicus.eu", vapply(seq_len(nrow(myfiles)), function(i) if (!is.na(pidx[i, 1])) substr(myfiles$current_path[i], pidx[i, 1], 9999) else myfiles$current_path[i], FUN.VALUE = "", USE.NAMES = FALSE)) ## where local copy will go
+    myfiles$was_downloaded <- FALSE
+    if (verbose) cat("\n", nrow(myfiles), " file", if (nrow(myfiles) > 1) "s", " to download\n", sep = "")
+    ## for each file, download if needed and store in appropriate directory
+    ok <- TRUE
+    my_curl_config <- build_curl_config(debug = FALSE, show_progress = verbose) ##, user = thisds$user, password = thisds$password, enforce_basic_auth = TRUE)
+    fidx <- file.exists(myfiles$local_filename)
+    myfiles$existing_checksum <- NA_character_
+    myfiles$existing_checksum[fidx] <- vapply(myfiles$local_filename[fidx], file_hash, hash = "md5", FUN.VALUE = "", USE.NAMES = FALSE)
+    for (idx in seq_len(nrow(myfiles))) {
+        this_url <- myfiles$url[idx]
+        this_fullfile <- myfiles$local_filename[idx]
+        if (!this_att$dry_run) {
+            this_exists <- !is.na(myfiles$existing_checksum[idx])
+            download_this <- !this_exists
+            if (this_att$clobber < 1) {
+                ## don't clobber existing
+            } else if (this_att$clobber == 1) {
+                ## replace existing if server hash does not match that of local copy
+                if (this_exists) {
+                    download_this <- !isTRUE(myfiles$ETag[idx] == myfiles$checksum[idx])
+                }
+            } else {
+                download_this <- TRUE
+            }
+            if (download_this) {
+                if (verbose) cat("Downloading:", this_url, "... \n")
+                if (!dir.exists(dirname(this_fullfile))) dir.create(dirname(this_fullfile), recursive = TRUE)
+                myfun <- warning ## if (stop_on_download_error) stop else warning
+                req <- httr::with_config(my_curl_config, httr::GET(this_url, httr::write_disk(path = this_fullfile, overwrite = TRUE)))
+                if (httr::http_error(req)) {
+                    myfun("Error downloading ", this_url, ": ", httr::http_status(req)$message)
+                } else {
+                    myfiles$was_downloaded[idx] <- TRUE
+                }
+            } else {
+                if (this_exists) {
+                    if (verbose) cat("not downloading ", myfiles$filename[idx], ", local copy exists with identical checksum\n", sep = "")
+                }
+            }
+        }
+    }
+    if (this_att$dry_run && verbose) {
+        cat(" dry_run is TRUE, bb_handler_oceandata is not downloading the following files:\n", paste(myfiles$url, collapse="\n "), "\n")
+    }
+    fls <- myfiles[, c("url", "local_filename", "was_downloaded")]
+    names(fls)[2] <- "file"
+    tibble(ok = ok, files = list(fls), message = "")
+}
diff --git a/R/utils.R b/R/utils.R
index 859f556..46960a7 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -3,14 +3,11 @@
 ## not exported for user
 
 ## file checksums
-file_hash <- function(filename,hash="sha1") {
-    assert_that(is.string(hash))
-    hash <- match.arg(tolower(hash),c("md5","sha1"))
+file_hash <- function(filename, hash = "sha1") {
     switch(hash,
-           md5=as.character(openssl::md5(file(filename))),
-           sha1=as.character(openssl::sha1(file(filename))),
-           stop("unexpected hash type",hash)
-           )
+           md5 = as.character(openssl::md5(file(filename))),
+           sha1 = as.character(openssl::sha1(file(filename))),
+           stop("unexpected hash type", hash))
 }
 
 ## NA or empty string
diff --git a/man/bb_handler_copernicus.Rd b/man/bb_handler_copernicus.Rd
new file mode 100644
index 0000000..d0c4c71
--- /dev/null
+++ b/man/bb_handler_copernicus.Rd
@@ -0,0 +1,25 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/copernicus_handler.R
+\name{bb_handler_copernicus}
+\alias{bb_handler_copernicus}
+\title{Handler for Copernicus Marine datasets}
+\usage{
+bb_handler_copernicus(product, ...)
+}
+\arguments{
+\item{product}{string: the desired Copernicus marine product. See \code{\link[CopernicusMarine]{cms_products_list}}}
+
+\item{...}{: parameters passed to \code{\link{bb_rget}}}
+}
+\value{
+TRUE on success
+}
+\description{
+This is a handler function to be used with data sets from Copernicus Marine. This function is not intended to be called directly, but rather is specified as a \code{method} option in \code{\link{bb_source}}.
+}
+\details{
+Note that users will need a Copernicus login.
+}
+\references{
+https://help.marine.copernicus.eu/en/collections/4060068-copernicus-marine-toolbox
+}