They were very popular at the time and the company continued to manufacture them until about 1941, when the company started to manufacture items for the war effort due to WWII.
They did manufacture marine clocks as far back as October, 1865, when the Seth Thomas' Sons & Company was formed specifically to make the marine clocks and other "high-end" clocks. But, if your clock has the bells, it did not come from this early on.
The 1884 date is the first year that the "bells" were added. The clocks made at that time were lever-escapement, with a balance wheel. These were made for many years.
The ship's bell clocks that were made after WWII by various companies that owned the Seth Thomas trademark at the time, were "platform escapement" with jeweled (watch type) balance wheel.
As far as selling your clock, eBay would probably get you the best price, fast. You may also sell it locally on Craigslist.com or even at a local antique store that may sell it on consignment for you.
I hope this helps.
Thank You by: Anonymous
Thank you for your information. I do appreciate it.
Australia by: Max
I have an identical clock, a trigger on the left is to co-ordinated the bells of the watch (1 to 8 bells) I think you have a 1935 Merrimac.