No run training for consistent blocks

Long story short-

I work on a tug boat in a 3 week on/3 week off schedule. My primary focus is triathlon. When I'm home I can do all the training I want. On the boat I'm unable to do an running. We have a stationary bike that i use liberally, some free weights and kettle bells, a jump rope, and some elastic bands I use. At the moment I generally do 4 or 5 days on the bike, 2 days of plyometric work, and one day of running drills (there is about 100ft length of deck I'm able to things like various ship drills, high knees/ butt kicks and such). I can't do speed work in that 100ft as there are too many tripping hazards and technically my captain won't allow it.

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I just did a 70.3 and I was disappointed with my run but definitely not with my bike. I'm looking for help how to up my run training game while I'm on the boat.