Years ago I owned a couple of Tartan 30s, and they had a similar arrangement with a steady bearing about midway along the shaft. Originally these were split pillowblock bearings with babbet bearing material. The grease recommended by Tartan was " Lubriplate water pump
grease" a fairly light white grease. The grease was fed to the bearing with a manual grease cup. As the bearing had some wear, it took a twist on the grease cup every few hours to keep the bearing quiet.
Later I replaced the babbet bearing with a ball bearing pillowblock, and swapped over the grease cup to the new bearing. Then I went to waterproof wheel
bearing grease and gave the bearing a shot of grease every couple of weeks. This worked great. No noise
or vibration and the slight layer of grease prevented any rust from forming.