The writer messed up

You can't isolate a ship by showing nearby ports.

Don't add a character with experience and wait to tell the situation.

Anna doesn't inform anyone of the issue until three victims become subject to Dracula’s plot.

Either make Anna Renfield (dumb) or don't include the character. As for the the issue of the ports, Don't include the option. The book kept the ship under the constant struggle of a storm that pushed them forward stating England was the closest and only port. Adding the extra stuff under cut the plot.