One of the possibility to think would be mold in the boat (if you had encountered any). Molds can cause varied symptom complex;
1) Allergic nose inflammation (allergic rhinitis); runny and itch nose,
2) Allergic conjunctivitis; itch and runny eyes, redness / pink eye
3) Bronchitis; cough
4) Asthma; wheezing
5) Enlargement of glands in neck and throat
6) Ear infections or ear discharge
7) Purulent (bad smelling) sputum / phlegm or cough,
8) Breathlessness (dyspnea),
9) Low-grade fever,
10 Chest pain,
11) Blood in sputum (hemoptysis),
12) Sense of non well being (malaise)
13) Widespread aches and pains,
14) Loss of appetite (anorexia),
Following consideration also may help;
a) Pets need to be removed if there are any.
b) Control of indoor humidity may provide the best avenue for dust mite and mold abatement.
c) Cockroach control (if present).
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