Seawind1370 Mast CrackRepair

On August 8th, 2025, a Seawind 1370 arrived at our Seattle docks after sailing across the Pacific Ocean all the way from Thailand. The owners of this catamaran hired Beyond the Sail to conduct a rigging inspection after their long journey and before their cat was to begin a sail south.

We stopped in our tracks when we sighted a 15mm vertical crack in the aluminum spar and began preparation to unstep the mast. The cause of this finding was due to the mast base riding toe-heavy on the mast step plate, possibly from the 1X19 stainless steel wire shrouds stretching when settling together, or possibly from the initial tuning. At this moment, it was unimportant to us what caused the mast to ride on the toe; we needed to get this mast off.

The cracked aluminum spar foot would need to be removed; no other options except an entire replacement. Our plan was to cut off the damaged section and install a spacer plate below the mast step to compensate for the removal of 20mm of spar. Rudnick MFG assisted us in the cutting of the spar, using a large metal bandsaw on jacks precisely leveled to our cut line.

Adding to our work order, the catamaran builders requested that while we were making the repair, to decrease the mast rake by .5 degrees to a 4-degree rake in an effort to relieve some of the weather helm that was occurring.

Seawind Mast Repair:

After cutting and filing the mast foot to an even finish, it was time to mill the spacer plate. Again, we headed to Rudnick MFG to use their skills and their Haas TM-1P CNC mill to create our robust plate from a single block of aluminum.

And Success! CSR Marine stepped the mast the following afternoon, and we were very pleased with the results. Over the next 2 days, our team re-tuned the entire rig to sit flush on the mast step, re-installed the boom & rigged the sails. The owners were able to head south before the fall winds arrived and are now sailing the Sea of Cortez.