what 's wrong with the "boats"?
The boat icons you don't like, but the sea attack routes (like the one on the California peninsula !) are ok ?
Or do you dismiss all the suggested sea attack routes ?
For me , I think the sea attack routes are needed (Cuba -Mexico very important !, MaryLnd-NovaSc also important and realistic (naval bases up there), Ecovil-Victor ..not necessary at all) as it creates (as always with the USA triangle shape) THE succespath for the map: start in the (south) corner with small corner zones (Cuba, New England..and Mexico bit bigger) having rear backed and seeping into the next middle large zones (Quebec, Democr---Libert --Tex, Libert).
You can argue about "pirate revert to neutrals" but the naval routes (at least 2 of them) are an asset to the map.

Barbarus hic ego sum, quia non intellegor ulli.